Thanks for all the good info, Scorch & Gew - I'm glad I stirred things up a bit.
P.S. I *still* can't decide whether to build my long range gun in 6.5-284 or 6.5x55 swede. It will be one of those two however, in all likelihood. If I run with the 6.5-284, then it will be in the form of the 30" bbled Savage 12 F Class Precision Target Rifle. If, OTOH, I end up going with 6.5x55 swede, I don't know what platform I'll get it in - I'm leaning toward a heavy-barrel T/C Encore, but I don't know if this has the accuracy potential of a good bolt action. I'm think I'd better stick to a bolt, but don't want to pay the expense and deal with the hassle & waiting of a custom rifle. I want a poor-man's long range rig. In fact, if I were going to buy a custom barrel, have it mated to an action, bed a good stock to it, etc., then I'd just go ahead and run with 6.5-'06 instead like Gew98's rifle, since a custom barrel expense is the same regardless of wildcat or not. And dies are the same cost regardless of wildcat status. So therefore it's looking like the Savage, since no crazy-accurate economy rigs come in 6.5 swede - bah.
I do think that the 6.5-06 has a bit more oomph over the 6.5-284 when comparing apples to apples pressure-wise, IIRC.