CF is not so fast. It has no moving parts.
It won't do read/write reliably in the long haul, but
some believe a CF boot drive makes some kinds of
devices more reliable for server apps, where they
are doing read only operations, or ocassional updates...like a routing table or something.
A seriously fast CF is 4MB/s
whereas a seriously fast hard drive can hit 61MB/s transfer rate...yes, thats an expensive 15k scsi drive, high end, and you won't get it on an A1200!
More of a typical 'fast' CF would be 2MB/s-3MB/s, and btw, you can go all the way down to 150k/s so watch what you buy.
The CF would be neat as a boot drive, and seek times I imagine, would be pretty good.