I have been using Spice D88-Gold for a year. It is a decent mobile for its cost with a power packed features. I use it with two sim cards tata and airtel and I have not faced much of problem in the usage between both the sim cards.
Can receive calls in both simultaneously and can put in hold one of the call easily. It had a decent quality of camera and music player. Sound quality of the earphones is good. Battery backup is not really good but withstands for a day and half.
Pros:
Usage between both the sim is easy
Looks Good
Have an additional battery which helps when I go on a long travel
Good MP3 player
Decent 1.3 MP camera
Cons:
Volume seems to bit low even at full volume. This is not a big issue since loud speaker is there. This mobile makes a good sense instead of the Chinese handsets which does not have warranty and IMEI number. Solved my pain of carrying two mobiles and chargers :) and maintaining them.