Yes, as Epic said, I coached for the Mahre Training Center for about 15 years, when it was based in Keystone. And in my (biased?) opinion, it really was an excellent program, and one that improved every year. Phil and Steve Mahre were involved from the outset, along with their team-mate, Pro Tour racer, and NCAA champion Stephan Hienzsch, who directed the MTC through its first decade-plus. But the biggest reason it became such a great program was the constant refinement from the same core team of coaches over the years.
When Vail Resorts let the Mahre Training Center go a few years back, they moved it to Deer Valley, and started to rebuild the program. At first, with all-new coaches, there were some snags. Many of the participants who had attended the program year after year knew more about it than the coaches did. But now that they're in their third or fourth season, I suspect that it's improved and once again become a first-rate program.
The Mahre Training Center is decidedly not a race camp, although we always had a group or two who were focused mostly on gates. It is a skiing performance camp, intended to develop the solid fundamentals of great skiing in all conditions, all situations, all over the mountain, for intermediate to expert skiers. We did use gates as drills, because there is nothing better for adding discipline and precision to your skiing and for measuring progress. We had a progression that started out as a linear sequence of drills, but became more of a philosophical guideline over the years, as each coach modified and adapted it for the needs of each group and student.
I suspect that the Mahre Training Center at Deer Valley is a very good program now, especially for the mixed aspirations of you and your father-in-law. There are more focused race programs around, including the one at Jackson Hole that Bob refers to above. But I think that the approach of the Mahre Training Center, focusing on fundamental skiing skills, is as relevant for racing as anything else. And frankly, in my opinion, many of the participants at "real" race programs would benefit more from some time out of the gates, developing their all-around skills. (Oops--did I type that out loud?) Either way, if racing is your focus, just tell the program director at the MTC that that is your goal, and you should end up in a group of similar intent.
If I may, and while I'm still a big proponent of the MTC, I'd like to suggest our own EpicSki Academy as an excellent alternative to the Mahre Training Center. While the MTC uses the best coaches/instructors at Deer Valley (along with, of course, a brief session with Phil or Steve themselves), the ESA brings in top coaches from across the country. Both are group lesson formats, but unless they've changed it significantly at the MTC, the ESA groups are much smaller (typically 4-6 at ESA, 6-10 at MTC). I think that the costs are probably similar, but the smaller groups make the ESA a better value.
Of course, at present, the only Epicski Academy in December is the two-day "tune-up" academy in Stowe. But that's just up the road from you--why don't you give it test drive, and then see if you'd like to join us for one of the week-long programs later in the season?