We played 4E for about a year before the group decided it wasn't for us. While we liked a lot of what 4E offered, the group gave it up as we felt the classes and powers played too similar and combats became too predictable (you knew who was going to win well before the combat ended).
Essentials addresses the former concern. Classes that were formerly balanced at a fundamental mechanical level are now mechanically distinct - the melee types are back on the reservation, though it remains to be seen of the primacy of casters at higher levels has been restored, they do get a couple of their old tricks back at low level. It's particularly clear with the Fighter. Where the 4e Fighter was almost caster-like in having to husband daily and varied encounter spells ('exploits'), the two Essentials builds play more like traditional Fighters - you hit things, maybe you occassionally hit them particularly hard or put a little english on 'em. Specifically the 'Slayer' build plays a lot like an AD&D fighter, while the 'Knight' build plays a bit like a 3e fighter. In both cases, it's more a similarity of 'feel' than of mechanics, but if you missed having fighters like that around, it could be a nice change.
The latter concern, not so much. Encounters in Essentials are balanced essentially (npi) like they were in 4e, PC victory is pretty nearly a foregone conclusion. Prior to Essentials, the MM3 introduced monsters that did more damage on average, which might make combats a bit quicker and more exciting, but probably won't much change the feel that bothered you.
The previews of the essentials classes peaked our interest. I figured I'd ask the 4E experts here if the essentials line changes would make it worth giving another shot. If so, which products would be best to start with.
Since you're already familiar with the game, there's no need to start with the Red Box, the underlying resolution systems are little changed. I'd suggest you pick up Heroes of the Fallen Land (ony 20 bucks) and see how the classes look to you - classes are probably the most significant change. If it looks good, you might pick up the MM3 or wait for the Essentials monster book ('Vault?') and try a few combats to see if the changes to classes and monsters add up to something you like.
Hope you like it, WotC has alienated a few loyal 4e fans in the hopes of getting you back, it'd be a shame if you didn't at least give it a try. If you don't want to invest in a book, you could just drop in to a D&D Encounters event. An hour or two on a Wed night. Just be sure to get a table where they're /just/ using Essentials builds (officially it's Essentials only but some DMs make exceptions).