If the drive has enough space, and the cache sizes are similar, lower seeks always get my vote no matter what the transfer spec is; ata100, 133, sata1, etc. Take for instance: huge sata 8 meg cache drive and an older and smaller 10k rpm scsi lvd raid0 array. The sata drive may max out at 60megs a second transfer of large files where the 2 drive scsi array will do between 40 and 50. Keep in mind the latency of the scsi drives is 4.5ms, the sata 8.5ms.
The scsi drives at 10k rpm typicaly have a 4ms latency, when you raid0 them it halves the latency. Latency is the single most important factor in drive performance. Notice that I didn't say drive reliability...
To answer your question, the drives are so close in latency it seems irrelevant. Can you test the drives with hdtach or iometer? That will answer your question as to wich is best.