Just to add to my above post (I was tired last night <img src="rolleyes.gif" border="0"> )
I've trained at PIK, Perth, Fife, and Cumbernauld. I have to stress that flying from PIK is far more fun, and far more worthwhile than flying from one of the other 3. Specifically because you simply aren't allowed to mess up procedures at PIK - they won't stand for it. It sounds acary, but makes you a much better and more confident pilot right from the start.
N.B. Theres nothing to quite match hearing "G-**** After the landing 747 line up and wait..." or hearing ATC tell a Ryanair guy he is number 2 on the approach behind a PA-28
(although hearing that does tend to make you wish you were in something a little faster!
The 2 runways are both obviously very long. Indeed, some interesting sights are often seen at PIK because of this. Some of my personal favourites from days when I've been there myself are an Aer Lingus A330 doing touch and goes in the circuit, ditto a JMC 757, and a Go-Fly 737, and an RAF E-3D, and 6 RAF Hawks (managed to get myself sat in one after they parked next to us!)
As you can probably tell, I really enjoy flying from PIK and it is hard to see any advantages the smaller air to ground radio airfields have over it.
However, if for any reason you dont want to fly at PIK, may I suggest Perth. I did my RAF FS there as I mentioned above. The airfield is as professional as small airfields get. It has 3 runways, as Circuit basher mentioned. Also, their main runway, 03/21 (from memory), is plenty long enough for a light single without having to sweat at all! GREAT food from the little cafe behind the car park, with friendly service. Their fleet of C152's are OK too.
Next, IMHO, is Fife - although calling it "International" kind of stretches the imagination somewhat!
I had my 'nastyest' experience whilst solo in the circuit there last year! It had a lot to do with being complacent about the runway lenght available at PIK, and errr, landing when I really should have gone around. (For that reason make sure not all your circuits are flown at PIK! CBN (Cumbernauld) is only 15 minutes flying time so if you're feeling very brave then you could pop in there) (if you can find the bloody place - its errrr, how can I put it, well hidden in an industrial estate).
But, and again as Circuit basher says, I feel that the number of runway(s), and width and length of it limits it's appeal to me. Also, I feel the same about the bloody stupid noise abatement procedure. Having said that I've only been in there a hand full of times, and I know that Rusty Cessna enjoyed his RAF FS there a lot!
However, he hasn't been up to PIK with me... yet!
With regards to Cumbernauld. I do everything possible to aviod the place. If you want to know more drop me a mail and I'll respond personally!
Good luck in your choice, you've picked a beautiful area to learn to fly over. I live in London, but all my flying has been done in Scotland, I love the place! Maybe see you at PIK some day.