As much as the CLS63 is a fast beast, it is completely different than the M3 and not anywhere near as much fun IMO. I have druven one on the track and it was surprisingly capable for a big car but it was big and felt heavy to me and not edgy enough. I would get bored of it as a daily but that is just me.
What about an M5? I don't know why that seems like a better compromise to me but it does. Having said that, I found the M3 to be a great and comfortable daily car and I would take it over the others you mention if for no other reason than it is a bit edgier and fun and doesn't feel like a big boat. All subjective.
2015 M4 | Austin Yellow | Black Full Merino Leather | DCT
2014 Corvette Stingray | Z51 | Torch Red | 7MT - Sold
2012 MB C63 Coupe | Performance package | Obsidian Black - Sold
2011 E92 M3 | Jerez Black | Fox Red | DCT | Competition Package - Sold