I am new to Prisms, and went PA 3X on my Tavor X95 because its already a fairly heavy gun. For up close work, it is maybe a few fractions of a second slower than a red dot. For targeting very small objects quickly (example, focusing on a doorknob while practicing), I find I can peer over the top of the optic with both eyes open, and then quickly be at the ready by just bringing the gun/optic up into position without losing focus, and consequently not taking any time to have to hunt for it. For something like human-sized center mass acquisition, I don't think its any slower than the dot.
If weight is a concern, I would try the prism if you intend it to be a CQB weapon. Worst case, you have way more room for a red dot with less offset than you would a LPVO.
If weight isn't a concern or you're more worried about further distances, I'd probably just go with the LPVO, recognizing you'll be spending a good bit more than the prism for comparable optical quality.