Originally posted by bozianul T
Is the difference between APS and FF so visible at wide-angle?
What difference?
For me, the main advantage of FF would be the better high ISO performance. All other things are minor and arguable.
With respect to wide angles, you just get a larger selection of primes. For example, for Pentax, you have the following prime lenses: 14mm, 15mm, 21mm - they correspond to 21mm, 23mm, and 31mm in terms of FF FOV - so you do not have prime lenses that can give you the equivalent FOV of a 14mm or 18mm on FF. Thus, on FF you have more selections of prime lenses in wide angle category. But given that on APS you have pretty good zoom selections: Sigma 8-16, Sigma 10-20, Pentax 12-24, it could be argued that there is no huge advantage for FF here overall as you can still cover the same focal ranges.