It may be the beans. I am no expert but have found that as the beans age you have to change the grind. If they are stale it may not make a great deal of difference. As you got them from a boutique roaster they should be fresh, but then again it would depend on how much they roasted then how long they were held before sale, Also the manner in which they were stored.
If you are getting grinds left in the cup then you are probably going to fine. If the crema is pale then you either have to tamp harder or go finer with the grind or your beans are stale.
But having said that how does the coffee taste even with the faster shot? If it tastes good to you, I wouldnt worry to much about the time it has taken. ;)