"The two times I have played 4e have been completely the opposite of that - zero description, zero flow, and books books books. Also indestructible characters and no sense of threat. Also the wizards were really really weak.So maybe you just had a really good adventure, and a DM who didn't care about the rules...?"
says a lot. I'd like to offer my thoughts here. Let's take this one part at a time.
1.)"Zero description, zero flow, and books, books, books." - I am not going to go into "yer doin it wrong". That's as non-constructive as hell. Instead, I will try and relate/describe how my experience worked out.
First, while I do lament the loss of the 500 word flavor text, I am sure most of it (at least for the iconics) is practically internalized for most of you. If I pointed to a bare stat block, and said, "It is 3 1/2 feet tall, green, talks in a squeaky high pitched voice, and is wielding a rusty short sword." What would be your guess? Of course, it's a goblin.
According to said stat block, they have a very limited set of abilities, depending on what type they are. The flavor is just that, flavor. Then again, why not make them blue, with rat noses, and lots of purple pustules? Use the same stat block. Now they are "Booglies" They can even be mixed and matched to keep the adventurers on their toes! I improvised that said minions had a belt pouch full of venomous "snacks" that they could throw (+3 vs. Ref.) for ongoing 3 poison damage (save ends). 3.5 had gotten us all used to being spoon fed EVERYTHING about said critter. This is no longer the case. The fluff and flavor is YOURS now.
As to the flow, this is a subjective thing I think. The flow was only a bit off during the first hour or so. Once the players got used to their character's abilities, it began to pick up FAST! We're talking 1 minute rounds here! Some of your problems are undoubtedly unfamiliarity issues, these will pass. Just follow the rules of fun and cool, and you will not fail.
A BIG help was using the Pre-Gen characters. They had all the 1st level selected powers printed right on the sheet. When they make their own characters, they plan on copy/pasting these: http://chadsblog.wordpress.com/2008/06/26/dd-4e-power-cards/ or doing as demonstrated for Magic:TG style flip/tap use. Hence the players only once referenced the PHB.
4E is a much more seat-of-the-pants style of gaming. It REALLY encourages improv within a loose and balanced framework of rules. Making the now brainless Inn patrons rise up during the last part of the fight was completely made up. The zombies as written don't do that. So what? I am the DM and I say they do! The looks on their faces were priceless though, EVERYBODY knows that victims of zombies rise again!
2.)"Indestructible characters and zero threat" - This was most definitely not the case for us. The poor dragonborn Paladin can attest to that! See, the trick is to challenge the party WITHOUT killing them. To do this, I had the main threats (the corruption corpses) and a bunch of piss-ant minions. The CC's are level 4 artillery. They had a nasty ranged attack, and guess what? In melee, they are truly nasty - their aura gives a -5 to attack rolls due to stench! They hid behind the wall of minions and pelted the party with chunks of necrotic flesh! The trick was to keep them shielded by their minions. The monster roles are VERY important if you want to challenge the party. Once you understand how they work, it makes it much easier to design a challenging encounter.
The goblin encounter later had 1 goblin hexer (lvl 5 controller) 4 goblin slyblades?(lvl. 2 lurker) and 12 cutters (minions) in a swamp clearing surrounded by thorny bushes, chanting and dancing around a bonfire. The party snuck up and killed a couple of minions before all hell broke loose. The hexer was actually a wee bit much for them, against a 2nd level party it would have been fine however. I had two party members down before the Cleric (DMNPC) was able to go around and revive them.
My experience is that combat is all or nothing. TPK or victory. Period. Dying in 4E IS hard, but is far from impossible. Remember, without help, you can only use 1 healing surge yourself & a second wind, per encounter. The cleric or Pally can help here, as well as healing checks, but that requires more teamwork - hence incentive based gaming. By using the wave tactics, I was able to work my way through those pesky Dailies and Encounter powers, as well as the healing surges. My new rule of thumb is "if the first encounter was too easy - throw another one at them right at the end." You'll see a little more desperation then.
3.)"The wizards were really, really weak." - Another throwback to the "old" ways of D&D. The wizard is not weak, per se, but re-tasked. See, his job as a CONTROLLER is crowd control. He influences the enemies movement, and causes a lot of AoE damage. Nobody else does that. Make sure that the word choice of "weak" is not just an instinctive reaction to his "colossal cosmic power" being curtailed to a point of balance. This is also a pretty subjective area. Remember that he is currently (IIRC) the only character that gets an extra Daily power, via staff or Orb too.
What it really boils down to is CHANGE. We have been doing it another way for so long, it is REALLY difficult to adjust. Personally, I have been drifting away from D&D for almost a year now. As a 31 year old full-time civil servant with a wife and two kids, a mortgage, and all the associated baggage, I simply didn't have the time to stat up a CR 24 Fiendish Red dragon / Disciple of Ashardalon. Much less it's minions, lair, and horde. 4E has been a god's-send to me. I also hear a lot of folks say that the players love it, but it's no fun to DM.
I hope my rambling helps to spur the creative juices in anyone who is having "issues" with 4E. It may simply not be your cup of tea. That's ok! Anybody else have these issues? Wanna chime in with homebrew solutions? Correct my hideous errors?