Downloaded and installed. Unusable on a high-DPI display. Normal compatibility setting changes not working and I've already lost patience with it.
You may have some trouble, then. Roll20 is easy to access, but if what you're looking for is a no-frills, token and map display for IRL games, it may be too VTT for you. That and learning to get maps to 'fit' can be a bit challenging. Creating new maps on roll20 is actually painful due to it's limited layers and how it handles which images on to the front or back. You have to learn a process to build a decent map on roll20 -- backgrounds first, then floors, then walls, then decorations. If you need to make a change after that -- good luck. I actually use GIMP to build maps (but I have a lot of art and enjoy building detailed maps, so...). FG's mapping isn't much better, but it is better. But it's even more of a tightly integrated VTT.
If what you're looking for a just a way to put a map on a display and move tokens on it, you might just consider just using photoshop or GIMP straight out. You'll get the resolution you want and it will be as intensive as you want it to be. It can be as simple as opening a map and token files and having at it.
All that said, I still like roll20 over FG. It's learning curve is simpler, which aids my luddite players, while still having some advanced bits I can fiddle with (API scripts and layered macros). It's fairly easy to use. And, it's online. That's actually a big plus for me because I've had my PC go down but still been able to run my game on my wife's laptop without interruption. Sure, the service might suddenly end and I could lose everything (except my art purchases, because I buy only downloadable packs -- I highly recommend Gabrial Pickard's stuff!), but the odds of that happening are slim and the convenience is worth the risk to me. I did the whole setting up a server thing with an earlier VTT and have no desire to do so again, so FG took a hit right off the bat for me for unnecessary annoyance of setting up the server and doing port forwarding. Still, the local only feature may appeal to you since you're working locally only anyway (ie, you don't need a license for other players to play with you).
There are plusses and minuses both ways. I don't have much stake in you picking roll20, so I've no need to upsell it. Be careful of some of the cheerleaders for both services -- they're more interested in selling the service (for whatever strange reasons) than meeting your needs. You might do better to start a thread with some requirements for how you want to use the system -- what's here is a little vague.