It's not as good as the masters. I have had the G1 feed's before and have seen the HITS feed's ITC before. They are as good as about anything else on W5.
You should not loose the G1 signals in snow if you have a big enough dish properly tuned. I would try to do some tweaking outside of your dish and feed peaking for maximum EBNO on G1's HBO's. That's how I peak my Azimuth on G1. Being in SE Wisconsin it would be the same as me in Chicago to use G1 for your low end of the ARC. I use AMC-3 (W3) for my elevation. That is my true south bird.
I have the same problem with G1, it sucks. I average 80-99% across the arc except for G1. G1-100 is about the best at 49-50% but it tails off after that and I too have a problem with snow and heavy rain. That's with a 7.5ft dish. On W5 most channels hit 94-99% with just 1 or 2 dropping to 88-90%.