I have used both and gotta agree with CG on this one TNE oil and water based are not the same thing...water is quite a bit faster...oil based is similar to prop
Technically, testosterone is not really suspended in oil, it's dissolved (even when there is no ester attached to the molecule). In water, the stuff just settles to the bottom of the amp or vial until you shake it. What you said makes sense since the difference between testosterone (no ester) and testosterone propionate (a very short ester) would not seem to be that great in terms of release times. I have not yet seen anything that would make me think it would be all that much faster although it definitely would be more rapid - although how much more rapid, I don't know. The fact to consider here is, once the testosterone is released from it's oily depot, ester or not, it becomes bio-available almost immediately. That alone says a lot.
Once hydrolysis occurs, the formerly esterified testosterone is now cleaved from it's parent molecule and is no longer soluble in the oily depot and begins to migrate to where water is - specifically, you.