I just bought a steam canner.
This one.
I canned 26 litres of salsa with it Friday evening and was very happy. It heats up quickly and maintains canning temperature with the burner turned down quite low. I noticed that the lid on mine didn't seal around the lip of the pot very well, so maybe it was losing more steam than it
should and I should have been able to turn the burner down even more and maintain temp. Maybe. I've never used one before so have nothing to compare it to. To keep a big waterbath canner boiling, I have to have the burner turned near to max, though.
This one has a gauge on it to tell you when the temperature is high enough to start timing. I like that because it can be hard to see the steam coming out of the hole in the lid (which is the other way to judge if your temperature is high enough) when the light isn't right or your lid doesn't seal so there's steam everywhere or whatever.
Bonus - it's stainless steel, so I actually used it to make the salsa in two batches, rather than the four batches it would have taken in my regular-sized stockpot.
I'm a steam canning convert.