I'm 5'7" and after inputting my detailed body dimensions the competitive cyclist fit calculator gave me the following frame dimensions:
-----------------------CompetitiveFit-EddyFit---Comfort Fit
Seat tube range c-c 48.5 - 49.0 49.7 - 50.2 51.4 - 51.9
Seat tube range c-t 50.0 - 50.5 51.2 - 51.7 52.9 - 53.4
Top tube length 52.3 - 52.7 52.3 - 52.7 53.5 - 53.9
Stem Length 10.2 - 10.8 9.1 - 9.7 9.3 - 9.9
BB-Saddle Position 69.8 - 71.8 69.0 - 71.0 67.3 - 69.3
Saddle-Handlebar 48.0 - 48.6 48.8 - 49.4 50.5 - 51.1
Saddle Setback 1.4 - 1.8 2.6 - 3.0 2.1 - 2.5
http://www.competitivecyclist.com/za...LCULATOR_INTRO

So the 49cm (seat tube c-c) Kilo should be at the low end of my range whereas the out of stock 53cm (which is the next bigger size) isn't even close...and a search of the forum shows that 49cm is indeed the size that many riders of my height are successfully riding with this bike.

Sure I agree that the Oxford 51cm appears to be a better fit, but I don't see where you get off saying that the 49cm Kilo is unsuitable for people taller than 5'4" because it also appears it would fit me (just not as well as it could if it were a hair larger)...what really concerns me about the Kilo is the crazy geometry: that wheelbase is shorter than my shortest folding bike! But what do I know about "normal" bikes?

EDIT: You guys were right I made a mistake here because the Kilo sizes are measured c-t which means the above table says the 49cm is too small...but after taking more accurate measurements I generated another table that says that I require a 49cm c-t and and 52.9cm effective top tube length...on the money.