With my boardman I only sized myself against the top tube and pretty much ignored the height of the seat tube - did that thing of sitting on the saddle, putting my hands on the top of the brake hoods and checking I couldn't see the hub of the front wheel at all. The frame looks pretty tiny and seeing as my height is made up of nearly all leg I have my saddle ridiculously high.... But I feel really comfy, never had any arm or back pain at all despite riding for 2 hours a day entirely on the drops.... So I'd def go with buying a smaller frame and hitching the saddle right up. :-)
With my boardman I only sized myself against the top tube and pretty much ignored the height of the seat tube - did that thing of sitting on the saddle, putting my hands on the top of the brake hoods and checking I couldn't see the hub of the front wheel at all. The frame looks pretty tiny and seeing as my height is made up of nearly all leg I have my saddle ridiculously high.... But I feel really comfy, never had any arm or back pain at all despite riding for 2 hours a day entirely on the drops.... So I'd def go with buying a smaller frame and hitching the saddle right up. :-)