I installed Rugby 2001 on 64-bit Vista no problem. the game runs great, and is improved greatly through the use of the nvidia control panel application specific settings. the only problem i have is the fonts. the front end of the game appears pixely, as does the text in the game, including the scoreboard in the game. it's readable, but doesn't look that good compared to the actual graphics of the game, which look superb.
the graphics and frame rate of the game are as smooth as butta. i think this game is an excellent simulation of rugby. if only Creative Assembly could have kept working on this game and made Rugby 2002, 2003, etc. Imagine this game with better looking rucks (the ruck mechanic itself is great, and more manual and intense then any other rugby game), and offloads and stuff. even though you can't call set plays on the fly, they work well within the system of calling the set play when play is stopped.
i am currently playing a World Cup on 50% difficulty. i've had some incredibly back and forth battles on 40 minute halves. the first time through i didn't make it out of the group stages, then i got more skilled at the game and i won the group and now am in the finals. one thing i really like about the world cup in this game is the format. did you notice that group winners get a bye and the other teams have to go through a preliminary knockout round? did you notice how the best 3rd place team of a group qualifies as well? (i think that's a fun format) if i win the WC, then maybe i'll try it again on 60% or 70% difficulty. i think as you increase the difficulty, the CPU does more consecutive passes on offense. (at least that's what i noticed when i tried an exhibition game on 70%)