I would have to disagree with the statement "Using SQLIO, or any benchmark tool, to get the maximum performance numbers from your system isn't that helpful...". I find using an extensive SQLIO test set, on a variety of IO outstanding values, for a variety of IO block sizes to be very valuable. Note that I recommend 10-20 minute tests of each block size, and I'd also recommend using up as much RAM as possible on the target server

First, it gives you an idea of what the maximum performance you can expect in each condition is, and how they relate to each other.

Second, it lets you test various configurations (RAID levels, # of drives, stripe size settings, FusionIO options, etc.) and see how they affect each individual IO case. This gives you more information for tuning each particular system.

Third, this technique highlights bugs, limitations, edge cases, and oddities in your particular setup. I once saw a system experience an unusually and inexplicably low write rate on certain cases, regardless of the spindle configuration or whether they were solid state or spinning platter drives. More "holistic" techniques would show consolidated numbers, and with those alone you would have a very difficult time figuring out that only one or two specific IO cases have abnormal results.