Hmmm... I don't know many folks who have made the switch in THAT direction. Usually its folks leaping from Pro Tools LE to Logic.
Workflow-wise, Pro Tools is pretty straightforward. There are a lot of key commands and mouse-click modifiers that you'll want to learn and that'll take a while... but you'll probably be OK with the interface.
PT LE, at least, is WAY more limited than Logic.

I'm sure you're read the list of things it CAN'T do. If you're OK with those limits and the limits of the hardware you can use...
Seems like an il-logical switch to me....

But I'm happy with Pro Tools for the most part.
Things I like about Pro Tools: clients don't ask me "Is that program as good as Pro Tools? I dunno, man..."
Things I wish Pro Tools could do without me having to spend a fortune:
- Timecode (DV toolkit? $1200? Un-fucking-believable)
- Unlimited tracks (What part of the "pro" did they forget to add to the "tools?")
- More than 18 i/o.
- Offline bounce! (Even though it "renders" way faster than video, anyway.)
- OMF import and export
Those are my thoughts. The question just strikes me as odd because I occasionally think about switching to Logic to get the features I just described.
Take care,
Chris