I developed an winforms program on w8 and just tried it on w10 for the first time, the following image shows how the text looks in the forms editor of vs2015 versus how it looks when the program is executed.
The text in the title bar renders fine.
I should probably mention I'm at 4k resolution with 150% scaling - I tried all the autoscalemode options and none did the job.
There seem to be ways to deal with this in wpf but in winforms I can't find any information, which is odd because this is presumably a common thing.