The ersa is the same way, but the LCD doesn't accurately reflect tip temperature in either case. I have a video I found on a German website that shows this pretty clearly using a temperature probe. The LCDs of both the ersa and the JBC show not much overshoot, but the actual tip temp shoots 65C past what the LCD says on the JBC. Granted, it was one model older than the current station, but I think they're still using the same heating/cartridge setup. Here is a youtube vid of the ersa on low setting:
As you can see it is fairly slow, about 15-18 seconds to recover from 250ºC to ~345ºC or so, but with no overshoot. That is with a fairly substantial tip though. I have actually tested my own with a thermocouple and recovery from 250ºC took 8 seconds on low with no overshoot, 5 seconds on medium with 12ºC LCD/6ºC T/C overshoot, and 3 seconds on hi with 75ºC LCD/65ºC T/C overshoot. This was with a 1.6mm chisel tip.
Here's where you can download the JBC vid:
http://i-tool.de/mediothek/videos/video2.wmvThey also have a hakko vid which shows about 55ºC overshoot on the same test but I forgot to grab the link.
Since the ersa vid didn't go down to the same temp as the JBC vid, I went ahead and re-did my own test with the iron LCD display dropping to 110ºC by being dipped into water like in the JBC vid:
On low setting, took 6 seconds with 17ºC LCD/20ºC T/C overshoot
On med setting took 4 seconds with 23ºC LCD/29ºC T/C overshoot
On hi setting, it took 3 seconds with 65ºC LCD/54ºC T/C overshoot
So the adjustable ramp settings are actually useful, it would seem, since the tips are interchangeable. Perhaps the JBC offers something similar that is profiled per tip, but maybe not, or it shouldn't have overshot so much. I wish I had access to a newer JBC to test this. I enjoy doing objective comparisons between pieces of gear.