You can get the ninja with the same specs as the Enforcer now. I have had a Ninja and it was a really robust machine. I have a Airflex Pro custom now which is also the same spec as the Enforcer. The Airflex is an easier machine to work with, and on if need be. I found the Ninja quite cramped inside. The Airflex also has bigger tanks which is also better, and the rear wheels are much bigger. It is surprisingly easy to get up stairs for a large machine. Another vital feature imo is it has a locking front caster which really helps on slopes etc..
The only thing it really lacks is a tank heater which you can get with an enforcer, however if you use it as a porty and fill with hot tap water the magma heater will knock out 110 degrees c