Questions on Karbonn tablet with sim card support

I am planning to buy a Karbonn tab with voice calling facility to use as a phone also. Why I am looking for a tab with sim card facility is simple, I do not want to carry a tablet and mobile always with me.

Whether SIM card support make any problem in long term? What will be the extra battery consumption? How many sim card slots are supported? Whether GSM and CDMA SIM are accepted? How will you rate Karbonn tab over micromax tablet with sim card? Sorry for so many questions but I think this is the right place to ask :)