In a choice between gas or electric cooktop I'd go gas every time!
My parents have gas and it's great .. it's immediate heat and immediate control when turning heat up or down
Unfortunately I've only ever had electric myself .. something that's about to be rectified when our new house is built with a gas cooktop!! Can't wait!
Electric cooktops take so long to heat up to the right temperature, never seen to get really hot (like you need for efficient wok cooking) and don't respond quickly when adjusted .. so if something is about to boil over and you turn it down you also have to lift the pan off till the element cools down sufficiently (where with gas you could just turn down the gas and leave the pot in place)
And once you've finished cooking and turned everything off, the electric elements take a while to cool down so are also a safety issue
As far as BTU goes, I have no idea there!