It depends on how high tech you need, if your regular CRT was good enough then in all likely hood the ACD will be fine, if you needed the artisan as a minimum for your work in the CRT days then you might need something far more expensive.
I think the photographers who are saying that the ACD is barely enough are working at a level that you will probably never ever need, especially coming from a regular uncalibrated CRT.
There are those who need the ultimate colour solutions in a monitor, those shooting for catalogues, for adverts, etc who need perfect representation. For me my CRT calibrated with the original Spyder was giving me (before it started dying) colour within 96% or better accuracy to the prints (some colours were slightly different, not that there was a colour cast) I was getting back from the lab, printed on a frontier and I would not be suprised at all if another 3% of that inaccuracy was due to profile mismatches on their side and/or chemistry/paper issues or maybe just the fact that you will never get a print to be 100% like on screen. I expect better from this new screen with the spyder 2 and any more differences will not be worth the extra thousands of pounds, not for my work, not for my prices and not to the level of accuracy that the vast majority of photographers actually need.
Remember that everyone who writes their opinion has an agenda, the opinion of a large catalogue house where colours of clothes have to be perfect is just not relevant to you (I assume), just as you didn't make sure to buy your film all from the same batch and date code, process in only one lab on a monday of the full moon, etc, etc to ensure the best colour consistency. Yes his opinion is valid - for him!
Maybe someone can back me up here but unless you have extremely exacting standards the ACR calibrated properly should be more than enough for you.