Been lucky several times to golf in Scotland...
Top Courses I've played...
Royal Dornoch - THE Best bar none -
Carnoustie - The toughest (Champ)
Loch Lomond - Lovingly set in a 350 year old Arboretum - stunning
Cruden Bay - Great Track
Crail - Classic
Machrie- On Islay, fantastic, and oh the Single Malts
I can't encourage you guys enough to play in Scotland at least once in your life. The golf is virtually all public and very affordable except a few mostly owned by investors. Book yourself and drive. Don't waste your money on the super expensive golf tours. Remember they do speak English, funny accent, but still English. Go in late May or June as you can play until 10pm or later especially in the North. A tip, the Scots eat dinner around 6. Play late afternoon and you'll have the courses to yourself. Castles and gardens early golf late makes for a great trip.
I went solo over to Scotland back in 96 to celebrate getting out from under a divorce. If I were to go back it would be August. You can still play late and Edinburgh is nuts with the Fringe Festival, Military Tattoo and other international festivals going on. Really a fun time.
Golf wasn't my #1 priority, but I did take my sticks and throw 'em in the boot. Played three of the St. Andrews courses (Eden, Strathnium, Old) and Loch Lomond. While the weather was fine for my week in Edinburgh, once I started north, things often got sketchy so I bagged a couple of rounds I was hoping for.
If it wasn't made clear watching numerous British Opens, it is almost a completely different game requiring creative shotmaking over target golf. And while the Old Course isn't necessarily a great challenge from a layout perspective, you will always remember playing the 17th and 18th because you'll never experience having to hit over a hotel or playing off gravel (17th) nor have a gallery of several dozen people surrounding the green (and politely applauding good shots) while walking the same little stone bridge as Arnie and Jack (18rh).
For someone going to Scotland with golf as your highest priority, just make sure you have good rain/wind gear. Including pants.
As an aside, I didn't book any rounds in advance. I just showed up. The round at the Old Course came about as I was sitting in a Turkish restaurant in St. Andrews and overheard a group from South Carolina on a tour complaining about the tour operator losing their bags. One of them decided not to play, so after talking with them for a bit they asked me what I was doing at 7:15am the following morning. It was about $60 back then, plus $20 for the caddie (who made my round - guy was a classic wry Scots comedian).