Well here are the talking points

The more watts the faster the water heater will recover... BUT the more AMPS the element will draw on your electrical system.. 1500 watts is about 12.5 watts. 2,000 would be about 16 2/3 amp over half your power on a 30 amp site, Does not leave much.

I use a 1500 watt 240 volt element, on 120 volts this is about 375 watts. I am on a 30 amp site, I anticipate no problems requriing I go out and reset the breaker sine the water heater is only drawing about 3 1/8 amps.. Sure it takes a bit longer for water to heat, but Time If it means I don't have to go out in the rain and play reset the breaker.