Having Shot with a 7D ...

[elflord]

I have been shooting with the 7D since it was released and now I am thinking of moving to a FF. From what I gather the 5D MII was a stellar camera and in may ways it still is. The question I want to ask... if the Mark III is an upgrade to the features that were lacking on the Mark II shouldn't it preform better?

I have the 5D Mark II, but I got it for shallow depth of field, and better image quality at mid to high ISO. For this, full frame DSLRs  excel APS-C cameras, it's really no contest.

However, for macro shooting and landscape more depth of field is desirable.

Also, I take it that you are likely to be shooting at ISO 100 ? Here it doesn't seem nearly as clear to me (but maybe someone who knows more about landscape/macro photography than I do which is a low bar, can help add some clarity to the discussion). Some of the better APS-C sensors outperform full frame sensors at lower ISO (e.g. Nikon's latest APS-C cameras have more dynamic range at low ISO than the 5D Mark II, though the 5D wins hands down at higher ISO)

[rlarsen]

I suggest you size up your priorities, and budget. How critical is equipment to your photographic needs. ? Is your current gear limiting what you can do ? Are you willing to switch brands and all your cameras and lenses every time new technology is released ?  What are the key features you require ?
I know photgraphers who use very high-end gear and shoot crappy pictures. Others use modest gear with extraordinary results.
The anticipation and  release of the 5 D MKlll has been very interesting especially with comparisons to the new Nikon. It reminds me of the guy who makes a lot of money at work and is really happy until he finds out a co-worker earns a little more.
I ordered 2 5D MK lll bodies, and I believe the up-grades from the MK ll and added features are worth the money. 
If anything sucks it's that I have to wait a few more days to get them.