"Thank you all for the inputs.It does, but you have to add at least couple of spindles. You can't cut the IOPS spindlecount in 1/2. is all which is what you do with raid 10, you only get 1/2 of the spindles in the disk group worth of IOPS. You get more consitant write speeds indeed. It is decieving becasuse most the time the data is written to controller cache too so on the back side it can wait for the write to actually occure while the server is on to other writes.
Based on the above info, to my surprise it seems RAID 10 does not offer any increase in performance!