Mtnl 3g Data Card

I am currently using wired MTNL Broadband Freedom 1295/- monthly rental plan plus taxes, which gives to me first 35 GB at 2 MBPS speed and thereafter unlimited download at 512 KBPS.
Currently I am paying Rs. 8,730/- per 6 months for 210 GB at 2 MPBS.

I am interested in opting for MTNL 3G Data Card (plug and play) with 180 days @ Rs. 4,500/- for 200 GB and with 1 year @ Rs. 5,000/- for 100 GB.

I have hesitations about:
1. Purchasing / Investing in MTNL 3G Data Card Dongle worth its value.
2. What types of models suitable with MTNL 3G. Locked / Unlocked.
3. I already have a 3G Jadoo prepaid SIM, Is it usable?
4. Currently, i don't have any complaints with my existing wired connection. Is the Data Card trustworthy and not a disappointment.

Spending Rs. 1,200/- though is not much, but I don't want to waste it, if Data Card is not trustworthy.

I want to use it for Desktop Computer and Apple Ipad through Wi-Fi. Not to be used in mobile.

Please clear my doubts.
I have not used MTNL, but when it comes to paying for a years service I always stay away form that, because with broadband connections there is no guarantee of how good it would work and till when. Go for the connection but choose the least time of recharge just incase the connection doesn't turn out to be as good as expected.
MTNL is a service provider which at times can give excellent service and at times fails to perform well and there are many users who get frequent disconnections. In my opinion get a short term usage deal and if all goes well then go for the yearly plan.
Reliance and Airtel are supposed to be good for datacard connection so give these a try too, but its important to know what the coverage is like in your area before you get the connection.