I haven't played the game pre-patch, however I'm enjoying Rugby 18 so far. I bought it a week ago at 60% discount, and although it has some obvious flaws it is fairly playable.
I personally found the pace to better than Rugby Challenge, since it does not feel so arcade-like. It needs one or two more patches to smooth over some small annoyances with subs and some game rules which do not seem to be applied consistently. But overall the game is fairly playable, and the buildup to my tries feel more natural than most other ***les I've recently played.
It is worth adding that I've played most other ***les, ranging from Rugby 08 through to Rugby Challenge 2 and 3.
The career mode would have benefited from a different design, and the overall presentation of it is a bit lacklustre. Personally I am still hoping for something similar to World Series mode from Rugby 08. Having said that, it still allows you to build up a team with limited funds, selecting from a very large pool of players across Northern and Southern rugby. Surprisingly a lot of club level players from the South are in the game, so I could build my SANZAR team easily.
If you're still on the fence, try it out. The fact that there was a patch which made a marked difference to the overall feel of the game is a good reason to support the developers.