I prefer cash. I do like a tournament from time to time. But i simply do not have the time to grind tourneys. Cash is simple, log-in, log-out at my pleasure.
Low on time, you dont like sitting for hours=cash. Long hours available, and youre like it=tournaments. Also with tournaments you need to be able to sit through few hours only to crash out at the bubble. This can be very tough.
If you learn to be good at both it would be a success. I'm talking about having good results and a positive bench. The fact of becoming professional on both sides is practically impossible.
I think it depends on many things, in my house I have time to play, that's why I choose tournaments, and I do well, but it is a harder modality than cash, which moves money every minute.