I have a 5D, but should I consider a 50D for live view?

I love shooting landscapes and nightscapes/astro stuff. Not deep space objects, just Milky Way, northern lights, wide angle and that sort of thing. I love my 5D but I really can't help but think how much easier focusing on stars would be with Live View. Anyone have any opinions? I think I could probably sell my 5D for as much as used 50D's are going right now.

I've sold all my lenses except a 50mm 1.8 mk 1, but this thought of switching really hit me when I was using the Sigma 24mm f/1.8 (or was it 1.4?) last summer on the milky way... the shots looked good zoomed in 10x on the 5D's LCD after the fact in image preview, but they were out of focus when I got home to my computer. The 50D's upgraded LCD would have been pretty beneficial, but how about ISO performance? I use 1600 on my 5D, is the 50D's 3200 acceptable, or is it going to be lacking form the smaller sensor?

I find that the 60D is great for AP, both for widefield AP and when attached to a telescope. The swivel LCD screen is very convenient for liveview. I'm not sure if the 50D has that feature. A used 60D would be about the same price as a used 5D.