One thing that should be mentioned is that buying characteristics up front is more expensive than taking them later with Dedication. Yes, you have to spend XP to get to the talent, but you are getting value for that xp spent.

Buying a stat from rank 3 to 4 is spending 15xp just to have it earlier than you would have otherwise.

That really is matter of pay-off now vs later.

Saying that most my group bought stats, mostly 3's and 4s, then spent the rest in talents.

Although our marauder took brawn 5 (now 6 thanks to dedication).