How "pro?" It depends on what you think "pro" means. If you mean good enough to take on paying clients without breaking the bank, then I'd say it ranks a 10. If you consider "pro" to be more like the kind of stuff you hear on the radio and hit records . . .
. . . then I'd say it's more like a 7.
That doesn't mean that a hit record couldn't be produced using one. Just that most aren't.
When recording digitally, you have to consider the quality of analog-to-digital conversion. The 1010's a/d conversion is about as good as $500 sound cards get. But keep in mind that most of the hit factories out there are working with stand-alone a/d converters that costs thousands of dollars.
Hook up a $5,000 Apoge a/d converter and a $300 Lucid Word Clock, and then I think you'll be looking at a 10. And these are things you can hook up to a 1010, so it's upgradeability is a very nice feature.
Don't get me wrong here. I'll be the last person to say that you have to have an expensive converter to get "pro-like" results. Actually, I'd even go so far as to say that most of the guys on this board who consider themselves pros would have to listen very closely before they could spot any difference (between a recording done with a Delta card and one with a $5,000 apoge).
That said, keep in mind that a difference exists, and that is one of the things that tends to separate the "pro" sound from the "project studio" sound. Ah, but there is always at least one exception to this rule, though, right? And this one might be it. It could be more like an 8 or 9 on your scale, as it's sound quality is often compared to that of very expensive outboard a/d converters. But it's still no cheapie in terms of PCI cards :
http://www.sospubs.co.uk/sos/mar02/articles/lynxtwo.asp
This one has me drooling. The Lynx II (or maybe III by the time I get the balls to spend the money) will be mine within the next two years, I have already decided.