I ordered a few packs of Perry and Claymore for a Westeros Lion Rampant project, and wanted to see if they'd also work for some Dragon Rampant with Bretonnians.
Here's a quick comparison.
Left to right: Perry Plastic Agincourt, Claymore HYW English, Citadel Metal Bretonnian, Perry Metal Agincourt, Claymore HYW English, Citadel Plastic Bretonnian
Claymore is a bit more slender, and about 1-2mm shorter than the Perry ranges. Their work on the old Warhammer lines are close, but have slightly more "heroic" proportions, especially the heads, and again slightly larger than Claymore.
~iPaint