Midland Beek,
Yes, lots available but not many at the value for money cost of the lid*l item.
Most are stainless steel, so technically a better material. Enamel finish is adequate for purpose, but would chip rather than dent if damaged and no longer be food grade.
Some have external elements but lots still have the older internal ones. Also many only have simmerstat controllers; the jam maker is much more precise, at least while operating with water as the medium.
It comes with a removable grid which sits about a cm or two above the vessel floor, so removes the possibility of temperature overshoot, localised heating and the honey bucket is kept clear of the temperature probe.
Of course, the dimensions are also important. The jam maker is a good match for the typical 10l honey bucket. I can get my 15l buckets in - just - but need to remove the handle. My honey settling tank will nicely sit over the top rim and is useful on the occasions when the last dregs require warming gently. - it would not want to be too heavy!
So, all in all, it suits my purpose. I can also melt wax or use it as a hot water source for beer brewing. I am able to make an extension to be able to use it with taller vessels (but clearly without increasing its liquid capacity), but I have no particular application, currently. Unfortunately for arfermo, it is not suitable, without modification, for fermenting wines as the temperature control does not operate below 30 degrees Celsius and it is is not tall enough (without an extension) for a standard demijohn.
Some of these items on epay, which appear from time to time, are the earlier version without the electronic controller (are served by a simmerstat, I believe). While fairly adequate, if closely supervised, they are most definitely inferior to the electronically controlled variants; they often sell for rather more than the new item, too.
RAB