I have used photon plus postpaid data card for sometimes and all I had was unpleasant experience. I purchased it in Delhi where speed was good but in other cities like Patna I got horrible speed.
When I called customer care they told that this city does not support postpaid service hence getting low speed which was 128kbps only. Same problem was faced in other cities in UP also. If they cant give service in state capitals there is no point in buying them. Data plans are also not very good, very similar to mobile Internet plans.