I actually just brought my old laptop (from 2009 when there was Vista) out of the dust and upgraded it to Windows 10, and I can't believe how fast it is now. So far i've only seen one bug, a small one where when you turn on the computer a little white box appears for a fraction of a second and disappears. So in my opinion I say do it! For me all its done is help so i'm guessing the same will happen to you.
The update itself takes about 3-4 hours which isn't that long. One thing i'm telling you should do is back up your files, I forgot to do it and I thought I lost everything, but somehow everything came back about 3 hours after updating. I'm not sure how, but do a backup just in case.
Hope this Helps!