I investigated machines thoroughly a few months back. I run a big TM, and wanted a top range porty as a back up. Given the power and cleaning efficiency of my TM, the porty had to come up to scratch. As well as things like vac and pump power, it had to be able to produce hot water and run with it. By that I mean I didn't want a slow inline heater that couldn't cope with the flow, like most hook on in line heaters. I broke it down to a choice between two machines. Ashby's Enforcer and Alltec's Evolution. Having been with Alltec for many years and knowing their reliability, I chose the Evolition. I also had all the extra's like auto pump out and fill. I have only used it once to now, as I said it is just my standby machine, but was very pleased with it. It is on the heavy side, so would be preferable as van mount, as a fully portable one you would need some kind of portable ramp to get it in and out of the van, and not suitable for stair climbing. On an average job you could just run longer hoses.
Hope this helps.
Dave.