Ascending the digital photography price ladder we go from equipment made to do almost anything reasonably well, to that designed to do a few things superbly. We wouldn't expect a consumer camera store clerk to give definitive advice on photographing art or fashion or food. We do expect more from the person selling us the latest MF kit, but that advice can only reflect what he knows.
If you don't do typical commercial photography, or if you are not exactly sure where your work is going, caveat emptor. In that case, very few people are in the same place or on the same path and can actually give you detailed advice. So, we haunt the boards looking for kindred spirits.
Dealers, after all, want to sell you something. Take the pitch in the spirit in which it is given. If the rep does not understand you any better than your spouse does, borrow or rent the stuff for a week and see what it can do.