Only if both characters are dps, then okay. Honestly though, your reward for going with any other friend is a smoother run, quicker queues, and playing with a friend. The bonus is from doing it solo, helping others, and getting out of your comfort zone. I'll use the thing i hear a lot of people say about mmos, if you don't want to play with other people, go play a single player game. It's not exact, but it's the same people complaining about pugs that just want to queue with friends or their FC and not stop foot out into it. I hope they never give any premade groups the reward.

I would support a random choice for premade or solo though, just not the same rewards.