The HD DLC takes over 4GB Harddrive space and 3 esp slots (not including the unofficial patch for it) which are the reasons why I never personally used it. I've watch my friend play Skyrim with it on his computer which has the same specs as mine an AMD PHENOM X4 955 Black Edition & AMD HD RADEON 6870 1GB RAM and I've noticed there were a lot of stutters here and there in his game even with the High Res DLC optimized mod from the nexus.

The only major texture and mesh improvement mod I have is Static Mesh Improvement, would it be better to get the HD DLC or opt for some mod instead like Skyrim 2k or Ultra HD textures?

No. I don't use it.

I use skyrim HD mod from nexus.

It has better graphic and performance than Skyrim HD DLC.

I'm assuming you are talking about this mod http://www.nexusmods.com/skyrim/mods/607/?

From what I heard it doesn't cover everything that the HD DLC does

Also what are people's opinions on this mod

http://www.nexusmods.com/skyrim/mods/35507/?

no since there aere mods that do a better job than the HD dlc and if you do be sure to use the unofical hd patch mod

for a 1 GB Card you shouldn't use HD texture Dlc game will stutter badly when your card runs out of Video memory better download other texture pack from nexus or some other place they dont cover everything but they cover the most your eyes will see most of the time

Bluh. Like people said, there's better mods out there that are optimized better and don't need an esp. Personally, I use Vivid Landscapes and the 'sixy' replacers. I'm not sure how high res they are, but they look nice and make the landscape more colourful. There's plenty more that stick to the original feel, though.

Also give aMidianBorn's textures a look for armours and a few landscapes here and there.