Ai have the 610 and I love it, one simple feature I love is the vibrate. Can run with head phones on and not have to worry about keeping an eye on the watch for the end of intervals. Touch screen works well and can't fault it at all. Tis on the expensive side though.
Had the 405 and we never got on, didn't like the touch bezel, and a had few units die on me. Although Garmin replaced them. 305 was ok but just too bulky, then before that had the 301 which was like wearing a mars bar on your wrist.
I like the virtual partner and would really miss that feature. I'm not bothered at all the touch screen. I'd be happy with the 405cx or 410 if they didn't have the poor scrolling method. I know I can lock it and put it on autoscroll but when paying that sort of money I don't really want to make do.
I think this question will have been covered before but I wondering did garmin solve the issue of the forerunner 405 scrolling by itself or not scrolling at all when wet or sweaty. I had a 405 and it would really annoy me when it did the above, then then battery packed in so I sent it back. I'm now thinking of getting the 610 but I was happy with the 405 other than the sweat issue. So could save myself a few quid with the 405cx if the issue was sorted with that model.