Be careful about the 'time to Command' bit. If a Command is what is important to you, above everything else, then maybe BA isn't for you. And between now, 2(?) years to joining BA and eventually getting your Command there will definintely (30 years in aviation speaking here) be a 9/11, Middle East crisis, running out of oil crisis........name your flavour of the month.
Understand that once in BA your airforce experience counts for nothing (if you stick to 'just' flying). You will progress up the seniority list just as slowly - or quickly - as everyone else. For someone who is a 'work hard, fly well & I'll be promoted' guy this can be frustrating, to say the least. Passing your check rides with 100% does not get you up the list any faster than the guy who passes with the bare minimum.
On the other hand, if you keep passing with the bare minimum you will climb up the list just as quickly as the guy who gets 100% every time.
In a Big Airline you get opportunities you can't get in most others: shorthaul one year, longhaul the next. Plenty of destinations. On the other hand you rarely fly with the same guys twice. If you want 'outside' work, there are plenty of opportunities in Training, Technical etc etc.
It's horses for courses, as ever, but if Command is what you really really want (the Spice of life??) then BA might not be for you.