Is it a keeper?

For a long time now I've known about the legendary qualities of the 5d mki but really after 5 years of being out and 5 years of new development by Canon how can it possibly compete with the latest and greatest of the x0d class bodies. A full frame sensor can only go so far right. I guess now with more expendable income in hand and the fact that the 50d prices are dropping quickly. I started to wonder if it was worth it to get a 5d since the price hadn't dropped much more and maybe it's price is near the bottom and sell the 50d while its value is at least near the same as the 5d right now.

Was able to find a reasonable priced 5d. I immediately took it home and started to compare the two. I setup a tripod and took out my 50mm f/1.4 and begin a simple test shoot. My object/model is the side of a xti box that I hope to sell soon. It has pictures and a lot of fine text. I basically used center focus took the shot and swapped bodies, using the same settings same position and lens. I then just saved the raw to jpeg and posted the images up. The lack of noise from higher iso on the 5d is amazing. The image was noticeably sharper and colors were more vibrant. Hands down the image quality coming from the 5d is better than the 50d. But why am I not sold yet.

The next issue that I face is if I'm willing to live without the 5 years of bells and whistles not found on the 5d. What I'm losing is:
Live view
2 sec self timer
Higher ISO range (not that any of it is really usable)
Greater FPS
Body with less clicks on it
More sensitive shutter button
More advance menuing system
Bigger and better LCD screen
More improved AF drive (maybe)
Extra reach with the crop sensor

I was able to go on a mini shoot with a friend. I was using the 5d and 135mm f2. At 10pm in the evening, it was pretty much dark out . I basically had street lamps and whatever light coming from a big red Panda Express signs around me. The AF was kind of slow and I had a hard time getting the focus to line up. Every time she would move I would have to refocus and it was painfully slow waiting for the AF. I ended up manually focusing my shots half way in. It could be that it was just too dark and I should have had a flash with me. Maybe it was the 5d, maybe it was the 135mm. Both items were new to me so it was hard to figure out what was going on or what was coming from which of the two items.

Hard call for some reason. I hope to decide some time mid month.