Is it a "must-have" tool? Not for me. I would expect to be able to do more with my $1,200 than mortise and loose tenon joinery. Festool makes some great tools - but that stuff is kinda pricey for a guy like me. I remember when cell phones, plasma TV's, computers, etc. were costly - but now all of those things are better and cheaper. Personally, I wait until competition drives down the prices. Nobody is proud when their old and expensive item gets outshined by something better at 10% of the price.
OPG3 Tweak everything!