I have the DVDs and the deck as well. If you're open to using gaffs at all, then buy them. The gaffs themselves are very good, and even if you never use them, the DVDs are very entertaining and give plenty of insights into card handling, sleights and performing that go beyond how to slip gaffs in and how to get rid of them.
If you don't like using gaffs, it's likely that nothing will change your mind. However, if you know anyone who gets the set, get together with them and check out the cards--the odds are that you'll still find half a dozen that you'd be tempted to incorporate into tricks you already know, or that you would want to build routines around. I was surprised to find some that were very clever, and that I hadn't seen in any of the other gaff decks I've looked at.
Now to put some money aside for FLOW...