Considering a different model. From Progasm to SGX?

Hello. I am thinking about buying a SGX. My first model is the Progasm. I am able to insert it fine but I don't think it fits me anatomically. I am a shorter guy (5'5") and I think the part that is suppose to push on my prostate goes past "the mark". I have reviewed the Aneros comparison chart. Out of all of the models available, I am thinking about the SGX because of the insertable length. It seems like all of the models are roughly 4" except the SGX which is approximately .5" shorter. The only other model that would interest me is the Helix Classic/Helix Syn. But since they are 4", I might be in the same situation as the Progasm. Another thing is that the P tab doesn't seem be flush with my perineum rather than free floating. I was expecting it to fit more like a glove.

When I insert the Progasm I get pre-cum but it doesn't progress more than that. I noticed that when I take it out after being in awhile, and I reinsert it... It seems like the bulb goes past a tingly area when it's inserted all the way.

Thanks for the suggestions.