the new power jazz 63V (15S...!) from Kontronik has a lot of clever features built in (unfortunately, no dynamic breaking, the boys must have run out of talent at that point).

here what they say:

"Even its appearance shows that it‘s a strong one. Based on the JAZZ software we developed an ESC like none before among Kontroniks product range:

13-63V, i.e. 18-45 cells NiCd/NiMH or 5-15S LiPo
The spilled housing of the Power Jazz 63V gives perfect protection against mechanical damage. Additionally it makes the Power Jazz 63V 100% waterproof.
The Power Jazz is 100% protectet against reversal polarity. The exchange of plus and minus of the battery, no matter how long, does not damage the ESC.
Continues power is no problem for a Power JAZZ 60V, cause it‘s protected against over heating. The internal fan cooling guarantees that also in closed bodies a Power Jazz 63V will not get too hot. For boats KONTRONIK offers a water cooling instead of the fan.
New electronic circuits „anti-spark“ avoid bothering sparks when connecting the battery. Advantage: no scare and no burned connectors.
6 mm2 motor cables guarantee less losses on the cables and mechanical robustness.
Compared with ESCs like it from other companies the Power Jazz 63V surprises with an excellent prize.The Power Jazz 63V is nearly undestroyable. A strong partner for all modelers having strong ideas. " end quote

so, adam, if you like the sparking, fine. maybe you are younger than i am i prefer not to scare myself to death everytime i plug in the thing! the 6mm connectors (also sold by steve neu in the u.s.) are very good, as long as you don't touch them. even dry fingers leave a grease stain and that reduces current flow on a polished contact by a country mile!

roger