I'm at Stirling studying Computer Science (been here for almost 3 years now and still quite like it) and I also applied to and visited Aberdeen. I agree you should visit. Part of my reason for choosing Stirling was that it indeed just felt a nicer, greener place than Aberdeen when I visited. As for being far away from home, I'm 500 miles from home on the south coast (I deliberately tried to get as far from home as possible- I was weird aged 17). But as I think about it now-
1) Staying local does really have its advantages, like not needing to lug masses of luggage about, the option of living at home for a while if money/accomadation problems descend on you, being able to keep the same job if you want etc.
2) Staying within 100 miles or so has a few advantages such as not needing to book trains 3 months in advance and perhaps having some of your old school friends at uni.
3) Further than that and it makes no difference if you are 101 miles away or 700 (just about possible in the UK).