What shifting do you find less satisfying, front or back? The components you list are decent quality and should shift very well, particularly when new. Perhaps all you need are some minor adjustments to make them work at their best. If the bike is new, take it back to the shop for a tune up after you've ridden it a few times and have let the cables, etc. bed in.

Higher line components are lighter and sometimes more durable but, in general, don't shift noticably better when new.