a lot of this has to do with body porportions, femur length upper body height, stem length etc. which I am sure you are aware of. actually the bike does look too small or your set-up is way off. just a guess if you are 5'10" or bigger then I would go with a 57-57.5 TT. If around 5"7"-5'9" a 54-56 TT depending on upper body reach.

I am 5'9.5 and ride a bik with a 54.2 effective top tube, fits me like a glove with a 100 mm stem. 2 of my other rides have a 57 TT and with an 80 mm stem.. femur length has a lot do as well with TTand setback whihc again would encompass your reach

inmo it is a good buy, you can also check out tsuanmi bikes and tiemeyer depending on what you want to spend for a frame.
jensen bikes
cambria has some good deals as well for frames & forks