Tallgeese_VII wrote...
Not both !!
Because you must have some preference, and have a favorite character that is either a biotic or a tech !
You can even look at your challenges to be able to tell 
OP, I did look at my challenges.
I play Adepts the most, closely followed by engineers.
Then there is a very big drop off with Sentinels, Infiltrators and Soldiers, which are about even amongst the three classes.
Then another big drop off for Vanguards.
I think what you are referring to are tech power kits versus biotic power kits as opposed to engineers and adepts.
In that case, if you play all characters fairly regularly, the game will bias you toward tech versus biotic, in your challenge scores.
Again, in my case, adept and engineer kits, the number of times I've played them, is about even, with a slight bias towards Adepts. Primarily because of the AJ and maybe the Fury. Without the AJ, the two would probably be dead even or even favor engineers.
If you look at biotic versus tech challenge, you get a different answer, because there are more kits that have tech powers. In that case, I have more tech challenge points than biotics.
But if I had to choose one character to play all the rest of my days in MP, it would be the AJ, so despite what the challenges say, that would make me an Adept.