onboard showers and super pitches

If you use a super pitch with mains water hook up I'm guessing that you'll never run out of water whilst showering but my question is, would you still run out of HOT water? I'm guessing the answer would depend on which hot water system you have, well my current van has a Truma water heater which holds around 12 litres or so. I always try to run this on electric.

The new van I'm looking at has the Alde wet system, would this be better at keep me supplied with hot water in these circumstances?