A530 vs A650 vs A670
First, do you absolutely need tri-mode or is an all-digital phone workable for you? a650 is tri-mode...a670 is all-digital.
The a650 doesn't have a front display. The a670 does. Is this a necessity or can you live without it?
The a650 doesn't have a camera. The a670 does. For me this is a cool toy, but not a necessity.
This being said, the 2 phones are comparable. The size is comparable and is nice and compact. The buttons are still large enough to maneuver through the menus. The a670 has good, solid reception and crystal clear voice clarity. The ringtones are fairly loud (some would disagree I guess, but I find them acceptable...