Choose P-5. I used to have both P88 and P5. I've sold P88 and kept P-5. It's my all-time favorite.
This is my gripe with P88. Yes, it is more accurate than P-5. But in a rapid shoot, especially with one hand, P-5 is more stable. This was the deciding factor, when it comes to field stripping and re-assembly, I can do P-5 with one hand, blind folded a lot faster and safer than P88.
I have busted my thumb, (almsot pulling the thumbnail out), have had springs and guide pin launched at me (missing by less than one inch, it could have caused serious damage to my eye!). Besides P5 has way better trigger, especially with DA mode.