I did the cream ale extract kit a couple of months ago and it came out good, I will do it again. Three weeks in the fermenter and three weeks in the bottle, my standard routine.
I wanted to try something different so after racking it to the bottling bucket with priming sugar I bottled half of it then added 2oz of cherry extract to the remaining and bottled it. It was OK, very light cherry flavor. Next time I would use more extract, maybe the full 4oz for the 2.5 +/- gallons.