So the reason we got this little gem was to use the vac-u-loc feature and attach it to a sex machine we've had for a few years. The machine uses the vac-u-loc attachment, and mounting was pretty straightforward. Once on, it definitely stayed put. As others mentioned, it is a little flimsier than anticipated (it is rubber, after all) and so the ol' in/out was more complicated than expected (though, once it was lined up and inside, this thing made me hum!).

The texture along both shafts feels right, and the softness of the material is comparable to most firm dildos but not silicone soft, so it actually fills you with a nice firmness. Unlike everything else though, we were most interested in the vibration. Sure, in and out is amazing (and yes, it was amazing!), but I was really up for the vibration. I was slightly disappointed in the fact that only the larger portion of the dildo actually vibrates, but of course you can't get everything you want. While the vibration is fairly strong, you definitely don't feel it in the smaller dildo. When we were "testing" the toy, I noticed the noise is a little louder than most (partly due to the material of the dildo, in my opinion), but for our use it worked fine (the machine is far from quiet, just like us).

Sure, you should probably use a condom (we don't have that issue, because we don't even share this toy between us, and I don't plan to have it last forever). I don't regret getting this addition to our collection, and I'd go so far as to say that I'd use it with a harness (none of ours are vac-u-loc, so I'd have to get the attachment just to fit it to our harnesses to test).

If you like DP, then I highly encourage you to try it!

My original writing was after using this with our sex machine, and had a somewhat limited scope, so we figured we'd try something new. While I still love the double penetrator and it's vibe, without a vac-u-loc harness to attach it to, the toy is relatively frustrating. Sure, the vibe works great, but the softness of the material definitely detracts from the fun. Overall, still great, but this is can be frustrating on its own.