Nathan 1X is deliciously thick and just long enough. I enjoy the texture and the slight curve to one side. It's a lot more filling than the Actual Size; I strongly recommend 1X if you don't want too much length but a much thicker girth. Very satisfying.
I've only put a small bullet vibe into a SquarePegHole (in Steve 2X but the same principle applies to my Nathan 1X) and it worked well. Luckily I put a dab of lube in the hole first because that sucker was a b*tch to fish back out lol. I've also used the hole as a place to insert my fingers, giving me a better grip on the base for thrusting purposes (in both toys.)
I was thinking of getting an attachment for a wand for inserting into said cavity, which should also be good, and I'm hoping I can get a nice fucking machine some day. Supposedly softer toys might be more prone to tearing when used with peg attachments so it's something I'll have to keep an eye on. I do notice the bottom of the shaft is a bit floppier and squishier but I think as long as you're gentle and don't twist it too much, and be careful with your fingernails inside, it should be fine.
The only bad news is that you need to dry the cavity before storing it (leaving it sideways for a while) and you'll absolutely need a peg-attachment if you want a removable suction cup (I tried a LustArts double-ended suction cup but the cavity reduces the pressure needed.) On the upside, it should be very secure once it's attached and you can buy a stronger suction cup.
