The high-end WD drives WD1000, WD1000 8 MB and the WD1200 offer quick data access at 12.8 and 13.2 ms. Please note that these numbers show the total time needed until data can be read, including head switching and rotational latency. (The manufacturers usually only advertise the seek time.)
The new drives provide a data transfer rate of almost 50 MB/s, and tremendous capacities. Currently, the WD1200 is the hard drive to go for, if price is not a critical factor. The WD1000 with 8 MB buffer is quite interesting for people that want to set up file or database servers, as such applications always benefit from cache memories. For normal applications such as office software and games, the advantages are quite small. Since the WD1000 8 MB is not available everywhere, it's difficult to tell how much the street price differs from the standard WD1000. If it's only a few bucks, then it may be worth it; otherwise, I'd recommend the standard version with 2 MB cache.
It's impressive to see how WD has rushed to take the pole position among hard drive manufacturers. Maxtor or IBM have always been the first to release high-capacity hard drives. Today, Maxtor is ready with 160 GB desktop drives (at 5,400 rpm only), while IBM lost the time-to-market race for their new models. Anyway, there is not much room at the top, and you can bet that neither Maxtor nor IBM will give up the race. Once we take a look at those drives, then we'll see how big Western Digital's lead really is!