Thanks, folks. Upgrading to a 5D MkII would be a long wait. I'd need to save up and maybe sell some lenses. The 7D I could get now if I forego buying a 70-200mm F4L IS, which would complete my range from 8mm to 200mm. I've been waffling back and forth on this since well before the holidays. But shooting low light shots at Gloucester Harbor north of Boston earlier this week showed once again the difficulty my T1i has with AF in low light. And that was with the excellent 24-105mm F4 mounted.

But you've given me more food for thought. Thanks for that. I'll keep grinding on it. The current break in lens prices ends Jan 7th, so I suppose I need to decide by then.

I did finally get some low light shots of the Fisherman. Love that 24-105.