I only have experience with vegging with t5's. One 8 bulb lamp I had 4 of each spectrum, the other I had all 8 with 6500k. I seriously saw very,very slight difference in growth, if I was going to say there was any difference at all, I would say that the mix'd spectrum plant grew a little more spindly....but very very minor difference...As for flower...Why fuck around? get a 1k digital ballast with a 99% reflective air cooled hood, and make sure to filter the air entering the hood, and keep your glass and bulb nice and clean...You will grow monsters! It is like why use T12's for Veg? Use some T5's...And you have seen the difference that makes....Go big, and keep it simple...
Also when you are burping your jars, give the jar a "slight" shake...listen to the sound it makes....This will tell you if the out side of the nugs have "wetted" out. If they are still dry, then let them go another day before opening the jar....I like the jar to be about 3/4's full, and not packed in there, rather give them some space, this will help with "wet spots" where the buds are touching each other...Keep it up man, you will soon have a system that works for you, and nugs to keep a smile on your face...