I use one with a 35mm adapter a lot. I LOVE the look of it. In fact, I like the look more than the HVX with the 35 adapter for the simple reason that the A1 shoots in 24f as opposed to 24p. It's essentially faking a film look, so IMO it looks a lot more like film than the HVX, especially with the 35 adapter. The HVX has always looked way too digital for me. Given the choice between the two, I'd take the A1 any day of the week.
It's also a very deep camcorder. It has a vast array of controls and when you learn how to use the custom presets you will find yourself getting some absolutely stunning images.
I think that if you go with the A1, you will not be disappointed. You will keep finding new ways to shoot with it and your footage will just keep getting better and better. It's also a pleasure to add upgrades to it. Before you know it, you will have a bad-arse rig on your hands.
There is one downside, however. The screen. It is absolutely useless. If you do buy one, I'd suggest getting an external HD monitor immediately to ensure that your image will always be in focus. Ikan sells some pretty inexpensive HD monitors, I'd look into that. I NEVER use that little POS screen. Just thinking about the time spent trying to find focus on that thing-- Blah! Never again.
Hope this helps.
Regards,
WalterWhite