That depends on how much you enjoyed and depended on using the two main techniques that were removed from Brawl, namely Wavedashing and L-Canceling.
I LOVED Super Smash Bros. 64, and always felt that it was the better incarnation of the two games. L-Canceling and Teching were easy as hell, and I like the way items are thrown in 64 as opposed to Melee and Brawl (Link was my favourite character in 64 despite his low tier-rating, because I could use bombs to do tons and tons of damage, as well as setting up combos and playing mind games, and I couldn't do that at all in Melee, Brawl has brought back my love of bombs though with the new knock-back mechanics). But once I got used to Melee's speed, and stopped accidently Air-Dodging while trying to L-Cancel (a habit from mashing Z over and over again to Z-Cancel and tech in 64), it really stuck to me. Then I discovered wave-dashing, and my opinion changed. I'd always felt that L/Z-canceling was a bit of a broken mechanic in the game and was indeed an exploit, easy to pull off and fair for sure, but an exploit all the same. Wave-dashing was the same thing for me, but a bit more tricky. Now, wavedashing is an obvious unintended effect in the game, and was never meant to be used in the manner competitive players were using it. On the one hand, it can be argued that techniques like WaveDashing help ALL characters, but in reality it only gives Top Tier characters more options than they already have. I used Wave-Dashing as a necessity to compete against good players, but I've never enjoyed it as a game mechanic.
Brawl has removed Wave-Dashing, which is a great thing in my mind, but also taken out L-Canceling, which, while still an exploit along the same lines as Wave-Dashing, I actually have always liked, but eventually it ended up feeling like a mandatory button-press after each move. The trade-off for no L-Canceling is less lag on really bad moves like Link's Dair, and no lag-time at all for other moves, meaning L-Canceling isn't needed for most moves, so the mandatory button-press is gone. Now, some moves still have bad ground-lag, but I view that as a balancing agent, and as long as I know which moves have lag and which ones don't, you can incorporate that knowledge into the metagame. The tradeoff for Wave-Dashing is the ability to FSmash (or any other move you want, for that matter) out of a quick-dash, which was essentially the best use for Wave-Dashing in Melee other than spacing, which can be done just as easily with basic walking/dashing/running anyway. We're also able to air-dodge multiple times in the air, and there's a dodge that hovers right above the ground (think it's down then shield? Or is just jump then dodge right away... It's in my muscle memory, not my actual memory LOL) that gives you a few frames of invincibility, so I think the tradeoff is fair in that regard too.
In the end, if you were attached on those techniques as a means to enjoy the game, you're going to be disappointed with brawl. But if you can understand that the game is more balanced because of these removals, and that you now have to be good at the game rather than relying on L-Canceling and Wave-Dashing to get a step above the people in your crew who don't know how, and once you realize that the game can be just-as, if not even more exciting with the new mechanics, you should be able to get over your misgivings and enjoy Brawl, just not until your initial attachment to WD and LC fades away.
