From using RT extensively the last year or so I have noticed two things, which often make me have to do postprocessing in Gimp after RT. Both of these have to do with the graduated filter, so I would wish for the following improvements:
Additional filter forms radial and bilateral (dark to light to dark or vice versa).
I know that radial is vignetting but there I lack the possibility to shift the center point. So either a radial grad filter or a shiftable vignette would be great.
The ability to mask the grad filter, using a luminosity based mask like the shadows/highlights tool does. This would allow to darken the sky without having dark foreground elements reaching into the sky, like trees or towers, turn black.
Here’s an example of what I achieved with Local Lab. It’s not perfect yet, but I think it’s usable most of time.
I used @Wocket’s photo from a PlayRaw contest.