I use some reversals, but I get choose these at random, and I never have more than 5 reversed cards in the deck. Sometimes, when a client shuffles the cards, they end up modfying this. So, what I do, is shuffle the cards a little, then give them to my client. I ask them to blend their energy with the energy of the deck, and when they feel ready, give it back. Then I shuffle it a little more and hand it back to them. I proceed to request that they cut the deck into 3 piles, and rub hands together until they're warm. Then, I ask them to slowly pass their left hand, (the receptive hand, usually, based on which hand they write with) until they feel one of the piles is the right one for them. They choose one, and I lay the cards out from there. This gets them involved, both energetically and physically, and my system doesn't get shot to hell.
I used to let clients shuffle their own, but I would have to instruct them as to keeping the cards all going in the same direction. This stressed some of them out, and disrupted the flow of the reading, sometimes,because they were more concerned with keeping all the cards facing the same way then they were on their question.
I know, maybe it's whacked. But I believe reversals can expand on a reading, but not if there are too many of them. Everyone has their own opinion about reversed cards, too. It's a hot topic around here!