Make up your mind before you go to Pensacola. Don't go to Pensacola to "give it a shot". You'd be sucking up a slot for a guy who really wants it. Plus if you DOR in Pcola, you will not get a combat arms MOS. If you want combat arms, you had better compete for it at TBS, because thats about your only shot.
Now, before all you nay sayers get your panties in a bunch............... there have been cases of guys getting combat arms MOS's out of Pcola, but they were guys who were NPQ'd or attrites due to flight failure (ie: they gave it 100% but didnt have the monkey skills to do it). Academic failures and DORs have a great shot at supply or adjutant; not that theres anything wrong with that.
Decide what you REALLY want and then give it 100%. Dont go to Pensacola if youre on the fence, not only will you waste your time and theirs, you will be eating up valuable MOS credibility time that will come into play for your selection to Capt and Maj.
Choose wisely