OMF files work OK for transfering files from one platform to another but there are several problems, no automation or plugin infomation is included, it is simply the layout of your tracks. It also has the effect of consolidating your audio and conveniently renaming it something totally useless - your nicely labelled "rhythm gtr 2 DT" becomes gobbledigook....
As long as you are not planning on going backwards and forwards again and again there are some easy options in both PT and logic for a quick transfer, logic has a "export all tracks as audio" function, and in PT you can select everything and consolidate (this will create audio files without any plug-ins on it as it simply glues all your regions together, the logic version however does an offline bounce so all your effects and automation are included in the mixed down files.)
I would say your decision should be based on what would suit your needs better; it can be said that PT is preferable for recording, audio editing and mixing, however logic is better for song writing, composition and sound design as it has better MIDI impementation and handles soft-synths/samplers really well. In fact having spent most of the weekend using Logic Pro 8 I can definitely say the whole audio side of things has come on leaps and bounds, and the sheer power of the new macpros mean that you can run huge sessions natively without any need for extra DSP....
Either way, good luck with your music making....🙂