The question equally applies to the RT - indeed, I think it is more relevant to the RT than to the Pro.
For those of us who bought the RT, we were/ are not really looking for a lightweight desktop and/ or laptop replacement. Take my case. When I bought the RT, I did not need a laptop replacement. I already had a laptop. What I was looking for was something that would add to my tablet-use capability (since I already have the Nexus 10). Since then two things have happened. The bundled Office suite and the TYPE keyboard allowed me to replicate much of my laptop functions on the RT. This was a gradual process of discovery. My laptop was then deskbound. I used it to access whatever legacy programs I need to. The second thing that happened is that very recently, my laptop (which served as my desktop with external monitors setup) failed. At that point, I needed a machine that (1) would be deskbound and (2) that would allow me to use legacy programs. Instead of buying a laptop, I bought my first desktop in years!!!! But this also meant that my RT has somehow in the midst of all this has become my de facto laptop and it is performing admirably. Remember that when I started out with the Surface RT, it was not my intention to use it as a laptop. In the rarest of cases where I may need access to a legacy program, I can always RDP into my new desktop machine.
So, if I had to do it all over again, I would probably opt for the RT - particularly the Surface RT. Why? I really like the slim lines, the weight, and the battery life. I also like the fact that it comes with the Office Suite, which is basically where I live in addition to the browser. Can all these things be improved? Of course! In particular, I 'd like to see MOX versions of the Office suite (without neutering any of the key capabilities); I'd like an even better battery performance and I'd like to see a better processor (yes, sometimes the RT does seem to struggle, but it is nothing major).