I must admit that it shook my faith in them, but every good company, especially if they are in a state of aggressive expansion, face major problems like this, and GM has weathered the storm fairly well.
The lesson I got out of it was to not put all my (hashpower) eggs in one basket! I'm now mining with two other companies as well. Yes, I plan on buying more hashpower from GM in the future--they are a resilient company.
Having several other "redundant systems" is just a smart idea no matter who you prefer, and one of the companies I'm mining with made a statement that they too have had to make upgrades to servers, technical problems, that sort of thing, so it's not just GM. Mining is in a period of aggressive expansion and we all just have to play it smart.
We are the modern day '49er's' and I believe our risks will be duly rewarded if we are patient.