Obviously, the pirate-theme is best for anyone who loves booty (and who doesn't mind bad pirate jokes). This is a very visually appealing vibrator. It's also pretty standard in terms of function. There is no curve to this vibrator for g-spot stimulation. There is no rotating head. There is no texture. However, there is an O-ring (though the toy only claims to be splashproof). There are also five different speeds and somewhat varying patterns to those speeds. The Katsuni even has the number 5 on it's singular push button to remind you of how many options you have.
1. Slow unbroken vibration
2. Faster unbroken vibration
3. Super-speed unbroken vibration
4. Pulse
5. 2 pulses and then vibration, repeat
I'd say the best use for the Katsuni is as a traditional vaginal vibrator. This means thrusting is a pretty good bet (though once again, there is no texture). Clitoral stimulation with the vibrations is also pretty good.
This vibrator is not meant for anal play as it has no flared base...and yes, I would worry about accidentally taking those rhinestones up the butt (though to their credit, they seem well attached).
As for beginners versus advanced users, I think many advanced users will find the functionality of this vibrator to be boring. In fact, my only interest in this was the pirate-theme. I think this is a good beginner vibrator though. It is not too thick, nor too long. It also has no texture, and it's easy to use. No instructions needed! Finally, I would not call this discreet nor travel-friendly. It's somewhat loud, the controls don't lock, and there is no emergency way to turn it off (such as other toys where you hold down the button for 3 seconds or whatever).

Katsuni is made of plastic, which is an 8 on the safety scale. It's non-porous and phthalate-free. It also has no smell or taste. Personally, I like the rigid yet smooth feel of this toy. Plus, it has a velvety coating that feels great against the skin and is perfect for sliding up and down the clitoris. This vibrator is also latex-free, which is a perk for those who are allergic. I think the velvety finish is definitely a benefit for any plastic toy. It keeps it from just sliding in and out with no stimulation due to the tiny bit of drag that comes with this coating. However, the coating also works well with your own natural lubrication and doesn't drag enough to need tons of lubricant. In addition, the coating really doesn't make this vibrator any harder to clean. Overall, both beginners and advanced users should find the velvety feel to be an attractive feature, though more advanced users might look elsewhere if they enjoy more texture to their toys in terms of dots, ridges, etc.

Eden gives some basic dimensions:
Length:
8 1/4"
Insertable length:
6 1/2"
Circumference:
4"
Diameter:
1 1/4"
Weight:
6.5 oz
I think this vibrator is slightly heavier than my other vibrators, but that's probably due to the 2 C batteries, which are heavy themselves. It offers decent girth and is thicker than many of my glass dildos. 6.5 insertable inches is more than enough...I don't come anywhere close to inserting this toy to the rhinestones, which is actually great for cleanup purposes.
The vibrator itself has a floral and skull design with the rhinestones circling around the base. There is one softish push button on the bottom. You must cycle through all the speeds to turn it off, so this isn't going to remember your setting or any of that.
I'm not particularly fond of what I would refer to as clunky vibration. It gets the job done, but the sound is a little annoying. It's like when you have a cold and your voice gets kind of weird. Basically the sound of this vibrator is a normal vibrator with a cold (hope that makes sense to some).
It works just fine as a traditional vibrator, but it is in no way discreet enough for someone to see it and not instantly know that it's a toy. It's not something I'd consider compact or particularly great for travel either.

It pulses and vibrates. It all works with one push button. Unfortunately, that push button is on the end of the vibrator, and therefore it's pretty easy to accidentally bump. In its description, it's called quiet, and that's really not true. It's more of a 3 on the noise level and can possibly be heard through a closed door. At least it has a 4 in terms of power to offset the discontent I have about the noise. I wish there was a way to turn off this toy without going through all of the functions. I also wish there was a way to lock in the settings because I happen to bump the base a lot while thrusting and find it frustrating to suddenly find myself on another setting. The vibrations do seem to carry well. This vibrator is not really waterproof though there is an O-ring. EF calls it "splashproof," which is quite a bit different if you play with your toys in the tub! Still, splashproof toys are a bit easier and less nerve-wracking to clean. I did clean mine in the shower with no problems, so it is at least splashproof. Unfortunately, I see this toy being a battery guzzler, but at least it doesn't get overwhelmingly hot.

Plastic in general is pretty easily cared for. It can be wiped down with rubbing alcohol, or it can be cleaned with warm water and some antibacterial soap. Then again, you always have the wipes or toy cleaner option. Plastic is compatible with water, oil, and silicone lubricant. I didn't find any information that suggests that compatibility changes due to the velvety coating. The box that Katsuni came in is good for short-term storage, though there is a pouch included in the packaging that can be used if you don't have the storage space for the whole box. This can come into contact with other toys without worry, which I appreciate. It also is unlikely to melt or deform in the sun or a warm area of your house (like jelly toys have been known to do). Basically, you'd have to melt plastic with a flame. I'd like to see some clear storage pouches for more artistic toys on EF, though I'm not sure how they could pull that off.

This toy comes in a plastic box with a pirate-themed background. The packaging is rather large in comparison with the size of the toy. There is a little plastic indented spot for the base of the toy to fit into, so it'll stay in place inside of the box. The back of the box shows the rest of the pirate-themed toy collection that goes along with this vibrator. There is a pendant, one called "Revenge of the Sea," one called "Jesse Jane's Pirate Booty Stroker," and finally one named "Jesse Jane's Treasure Trove." The treasure trove seems to be somewhat similar to the Katsuni's secret. There are also two DVDs that are displayed on the back of the packaging. I'm honestly very interested to know more about them. If you are looking for a storage pouch, one is included in the box, and it is black. There are no instructions with this toy, though I find it self-explanatory. Finally, this packaging has a recyclable symbol on it, so that should make those of you who are "green" happy.