Well... in terms of price and also performance levels, it's rated the following from medicore to best performance within the range
Type S >> Type R >> Type X
Type X being the top-most and more worthwhile buy compared to the others, customisable x-over, bi-amp able, good tweeters and decent mid-bass. Settle for nothing lower range than this if u are serious about getting a good setup.
Type R have a new revision for the '05 year and it have improved slightly in terms of it's tweeters and mid-bass but no where near the Type X. Very good mid-budget entry level comp set for it's price.
Type S, no experience with them, but being the entry level comp, it probably is, well, medicore in performance.