@FarhanL That's a tough one, both X1 and Pro being manufactured by HTC..
I guess you are interested in them because of their keyboards...well, Tytn-2 is an excellent choice in that area and it would cost much much less. I can't think of any feature that is missing in the Tytn-2, apart from slightly lower screen resolution.
Out of the two, Pro has better looks, and HTC is a dedicated WinMo manufacturer. Its' 3D TouchFlo has seen many generations and is quite advanced now. Customisations for this set are easily available on XDA Forums.
SE X1 is said to have a good user interface (9 home screens) but I haven't used it.
So my personal recommendation would be Pro, although there is very little difference between both. Please check if X1 has 3.5mm headphone jack, because that would be a plus point.