As a former hardcore Thundercats fan (I'm a casual Thundercats fan these days), I have to say that this show hit the nail on the head. It's what the original Thundercats should have been. There were a lot of non sequitur elements in the original show that were either removed or altered. The most annoying thing of all was Snarf and I love his new (mostly mute) incarnation. The animation was gorgeous too. No complaints there. Can't wait until we get more episodes, and here's hoping it does well. Maybe a Silverhawks reboot won't be far behind (fingers crossed).
My favorite thing? No real updates to Mumm-Ra's (pre-enhanced, at least) design because it didn't -have- to be updated. He always had a kickin' look. If it ain't broken, don't fix it. I love that the art/design team recognized this.