The DLC are few exactly because reception to it was so bad (to Slingshot DLC), so instead they shifted focus on whatever's next (seemingly a proper expansion).

Hopefully a good decision overall.

I havent unfortunately had the time to properly play the newest one too much yet - but from the little i have, i think the good old action point system from Ufo1 is the best in series. Bigger maps + better LOS as well.

The combat in new Ufo is good, but definitely dumbed down from the the original.

Its bit weird really actually, Ufo Apocalypses Real-time mode was surprisingly good as well and they didnt streamline the system itself much at all.

Hopefully the Enemy Within will bring back some of the old "complicated" stuff :)

I'd buy that! I preferred the setting in that game haha.

As far as i remember (never bought them), one char + a few missions & ability to recolour armour seems to be very weak DLC - not surprised at negative reception? :).

Elite Soldier Pack (Pre-Order DLC) is just customization. Whether you like it or not depends on how much customization you do for your soldiers.
Slingshot gives you 3 (or is it 4?) new council missions and an extra soldier, along with a few more customization options. Biggest benefit of the DLC is that you get access to more resources earlier on, though that may be seen as cheating by some.
Neither of the 2 DLCs are must have, though if you liked the game Slingshot may be welcome (for the new missions).

The recolor was preorder DLC to be honest. Slingshot was really the only DLC they released, and that was not received well yeah, for good reason. Nice to be able to get the blaster early but meh overall.

new info

http://www.ign.com/articles/2013/08/21/xcom-enemy-within-announced-tons-of-details

The ability to genetically modify your soldiers sounds great. It's in the line with the general feeling of reboot when I had been ruthlessly recruiting hordes of new soldiers to find a few PSI gifted, so I could throw them right into the boiling battlefield.

Is there a release date yet?

November 15th 2013. 86 days.

Edit: IGN says November 12th, but Official Reveal Trailer says 15-11-13

Awesome. Not too far away then ^^

These changes look great. Not only do you get some new gear, they also made some new maps and did some balancing.

You mention the genetic engineering but leave out the MEC?

I'm not really into mecha. I haven't even used robots in the vanilla game.

Sounds like a real expansion. Its not standalone is it?. Lots of stuff...might actually be worth it..

Surprised it's not a Terror from the Deep knockoff