I've never used one - I only suggested it from what you seem to be after/what you seem have to spend. I saw this http://www.macvideo.tv/camera-technology/i...pagType=samecat
yesterday and it proved to me once again, it's not the kit, it's the person using it.
Video seems to have largely moved from CCD to CMOS sensors and correspondingly, there are few companies making 3 chip gear. I know panasonic do. The bits and pieces I've read suggest that the reduction in individual chip size is more detrimental to low light usage than a single chip.
The Canon HG10 that I'm playing with at the moment has some real limitations. Manual focus is by Kinder Surprise wheel and cannot be done using the VF for instance. It has no histrogram, no zebra stripes, no audio control whatsoever. I have figured work arounds for most of the problems, most of the time, in the month I've been using it. It's menu based but much faster than my IXUS 850. Learning to actually shoot good video, edit it and everything else is proving the much greater challenge!
From what I can see of the A1 - you have proper audio controls, a proper focus wheel on the lense and a half decent mic as well as XLR options and time code for off board audio. I'm certain that a camera used in broadcast situations will have manual exposure modes, a histogram and zebras. Whether a 0.5x convertor will get you to 18mm I don't know. My HG10 has a 43-430 lens - really stupid! However, with a 0.7x, it takes me to about 28 - which works for me. A 0.5 would be 21.
As with all equipment purchases, it comes down to compromise. I ummed and ahhed, set a budget and bought the best camera I could within it. For me, by the sounds of things like you, that was the most control for the least money. I couldn't stretch an SR11 and the lesser Sony models didn't give me what i needed. If I have RED taped right - no matter what you buy now, you are going to want a Scarlet when it's released late next year. At $3000 it would appear to be a direct competitor to the A1. I would work on buying one of them ASAP and buying what you get now as a tool until your Scarlet arrives.