Nice review, thanks. I see if you are trading the SPX or VIX you are paying 1.79 in (.10 clearing fee, .04 reg. fee, and .65 exchange fee) and .79 out. So a net of 1.29 each way, if you close out a position. If you let it expire, you are paying the 1.79. The .65 they charge in exchange fees is the maximum the exchange will charge. It could be less depending on the price of the option or if it is weekly, but with them you will always pay this .65 maximum.
I also pay .50 per with TD Ameritrade, but I just got a "exchange pass-through charge" of $92.38 for trading SPX. That seems to be equivalent to 142 trades on TastyWorks with their .65 charge. Am I missing something?