Before you can even understand the answer to that question, you need to understand the basic differences between fixed-point and floating-point calculations and what advantages and disadvantages each has for digital audio. They're different animals and can't be compared head-to-head. Native versions of Pro Tools are going to do all their processing at 32-float regardless of your session settings, anyway. It's only about how the files on the disk will be treated.
Bob O is right (you can pretty much count on that around here in general
) that 32-bit float offers no greater resolution overall compared to 24-bit fixed. It offers a kind of variable or flexible resolution over a wider dynamic range at the expense of - I don't know exactly how best to express it - consistent precision? Something like that. Its main advantage is that it doesn't need to be dithered after each digital process. That means, if you do lots of Audio Suite processing or printing effects, layer after layer of multiple processes on the same files, then more detail may be preserved if the session is set to 32-float. Maybe. Remember that the session is going to take up 1/3 more space, and you will be able to play 1/3 fewer tracks per disk. So it darn well better sound enough better to make it worth that trade.
I can see 32-float sessions being an advantage in film work and sound design in some cases. That's about it.
A good book explaining all that in more detail is "Digital Audio Explained: For The Audio Engineer" by Nika Aldrich. Kind of expensive book but totally worth it. Your workflow will thank you henceforth and evermore.