I'm a pro-photographer but have always been a Windows user. A rare beast....lol. I'm also former photo faculty at a mid-west university too.
I use a SP4 for my work. Recently I actually migrated off my desktop rig just to my SP4 to see how that went. It's been great. I work almost exclusively in Lightroom, though, and rarely have a need to do work in PS so can't comment on that side of the house. My SP4 is the i7 variety with 16gb of RAM and 512GB drive. I'm using it with the surface dock and drive two external monitors at my desk.
I haven't had any issues, really. Performance is generally great, depending on the size of your RAW files. I mainly shoot in mRAW or sRAW on my 5dM4. Lightroom can handle those fine, though as my catalogue is growing, I suspect that will become more of a challenge. I generally have created new catalogues every three years or so, but I suspect that part of my flow is going to have to change with the Surface to keep my catalogue smaller. I did an architecture shoot this weekend that require full RAW files. Performance in editing was noticeably slower than with mRAW or sRAW files, but it did not impact my work flow much.
The biggest benefit for me is travel and mobility. As airline seats are getting tighter, editing and processing files on planes is becoming much harder. The SP4 solves that problem as it takes up so much less space on the tray table or on my lap. If space is really tight and I can deal with it, then I use it in touch mode with out the type cover. Adobe have done a pretty poor job of touch mode in Lightroom (IMO) and it slows my workflow down significantly. But when it comes to not being able to do anything on a plane or getting some stuff done, it's definitely usable.
Storage space will be the issue for me. I have yet to solve that. My desktop rig had three huge internal drives in it and I back up to Crashplan. I'm cut off from those drives now on my SP4. I rarely need to back to shoots, but I'm very conscious that it's going to be a pain when I need to. I need to solve that part of the puzzle.
The other annoyance is colour management. I use Colormunki Photo for management. Both monitors are profiles and the SP4 screen is profiled too. But switching between profiles is irritating in Windows. When I am docked I have to go into settings, select the profiles for the external monitors, then restart. When I unplug and go sit on the couch, I have to go in to settings, select the profile for the internal panel and then restart once more. It's a nuisance, but not a deal breaker.
Battery life is not an issue for me. It's not great; building previews, etc. takes a lot of juice. But I am never with a charger and I'm fully charged before getting on a plan. If there is no power on the plane, when the battery stops, so do I....lol.
So that's my experience. I hope it helps you. The benefits FAR outweigh the minor inconveniences.
Cheers!