I have an electric one and it heats up quickly, within 5 minutes or so. (I actually got it as a wedding shower present over 30 years ago, fondues were hot in the 70's.)
There is a knob for low to high heat. The cord does run across the table. I was always worried when the kids were younger, but we never had a problem.
The sterno ones I don't think would heat up sufficiently. But I never tried them.
And if you heat it on the stove, I think it would cool down too quickly.
The electric one tries to keep it at an even temperature--and since we always do it on a holiday or birthday, we do linger over dinner.
(To see if it is ready, you skewer a piece of bread and if it bubbles when you place it in, it is ready to go.)

It uses a lot of oil, that is annoying (I do try to reuse it, but I don't fry that often).
The family loves it.

I cut up pieces of sirloin or london broil and we cook our own. I have never tried chicken. I usually have an assortment of 6 dipping sauces (after you cook the piece to dip in)---like horseradish mayo, honey mustard, soy sauce, bar-b-que, orange-ginger, etc. Then serve it with a salad and baked potato.

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