Yes, you're right. So here is my math:
I just found that over the last year I drove 2083 miles. I divide that by an average 250 miles per full charge (I don't anticipate I'll hit 310 consistently as I have a heavy foot and want to be reasonable) results in 8.332 charges per month (this may be less - my driving is variable but has been around 1900-2100 over the last 7 years). At 8.332 charges at ~$11 per full charge (on 10kwh) I'm looking at ~$92 per month in electricity. Say I used the super charger near my office for 2/3rds of that at 10 months per year...so that's ~$60 X 10 X 2: $1200. That means the rims cost $300. So $1200 free supercharging or $1500 free rims. I may have to rethink my decision. If I chose to super charge for $80 a month, it would be in my interest to stay w/ the SC. It's really a tough choice. You may have a point.
With that being said, at 22kwh we're looking at 2400-3600 over the two years. I'm going to see if they will let me make my decision on which incentive I'd like to take by tomorrow.