The main problems IMO are:
- you can just go around again if you aren't sure which exit you need; you are forced into taking an exit, right or wrong
- the radius is too small so there is not much time to make a complex decision, especially if you aren't already familiar with the exits
- it's hard to monitor traffic entering the roundabout to make sure I don't get hit by someone having a harder time navigating this than me, while at the same time trying to figure out what the crazy sign diagrams mean.
- there's no confirmation when you do take an exit that you've taken the right one. Might not be a road sign for 10-15 seconds, which is a long time when you're not sure where you're going.
- they're even worse at night because there's not enough lighting. Not too bad for the exits toward civilization, but pretty confusing for the more rustic ones.
I think the idea is okay, but at least for the ones they put in here, the execution is not so hot.