In reply to IHaveADream: To be honest most Winter Courses are fairly similar no matter who you go with - 99% of the time they will be run by enthusiastic and competent instructors and all courses are completely beholden to the weather and the snow conditions.
As an individual you can't really go wrong with larger companies like Jagged Globe or with courses run by Plas y Brenin or Glenmore Lodge. They are well organised, well resourced, they employ experienced instructors and often include decent full-board accommodation.
That said, if there are two (or more) of you who want to do a course, especially if it is just part of a longer stay in Scotland and you will be arranging your own accommodation anyway, you could consider booking an individual instructor directly.
Look for someone who is a member of AMI (Association of Mountaineering Instructors) or is a British Mountain Guide and you cannot go far wrong. In either case, the suitable instructors will have the appropriate logos fairly prominently displayed on their websites or adverts.
Finally, take with a pinch of salt massively enthusiastic comments from people who have done such courses. You may get people telling you that the instructor they had was excellent and therefore 'the best'. Unfortunately, by definition, most people only do ONE Winter introduction course, so it is unlikely they have any real insight into how their instructor actually compares to others. As already mentioned, most instructors are excellent, but it is equally likely that any individual being recommended is no better or worse than the many other professional instructors out there.
As such, I would focus as much on issues of logistics (accommodation, catering, equipment, transport etc.) as worrying about the quality of instruction. I would also suggest, if possible, to book your course later (mid-Feb onwards), rather than earlier in the Winter season as you will have more daylight and generally better snow conditions.
HTH
