Well, I took both, and I can certainly give feedback. However, experiences won't be the same due to the instructors' differences.
The seminar is attended on a very short time interval. Depending on how you approach the class in terms of background and motivation, results will vary. For me, it was surpisingly more fun that I had expected. The class is definately more updated on techniques than the Home Study Course.
The Home Study Course can serve as a good reference point if you're in need of having some questions answered. You can always have something repeated if you want. And obviously, it's cheaper.
I cannot say what will work best for you. If you're on a tight budget, you won't miss out on too much if you stay at home and learn. It's a flexible learning system, and you can definately get creative with it even if you work alone.
Considering the potential reaping of rewards with this skill, I'd say both are great.
