I have the mini try-angle - I love it! It fits in a standard pillowcase, the carrying case is FANTASTIC, and it's a great little cushion. I use it all the time, even just for sitting in bed using my laptop!
We have the Try-angle and rarely use it plus it takes up closet space, we also found the angle too high for us.. We lie our Mini column better and have used it both missionary and doggy style. I'm going to make decorative pillow covers for mine to just leave on the bed all the time. It makes a great back rest for reading in bed too.
If I had known realized from the measurements posted how big it was I would have gotten the mini try angle. I think I even uploaded a pic comparing the Mini column to the try angle on the mini column page. Keep in mind though what didn't work too well for us might work for you.
Umm.. hard to choose something like this for someone else. We don't know ya'll's prefs! For me, the Lil Pony would not be ideal.
It'd help to know how you plan to use it, what types of positions you favor or else it's real hard to give any suggestions on which would be best for your personal needs. I personally like the Try-Angle because it seems you could do more than just a few or one specific position.