Nat
Don't be embarrassed about your Altec Pro 40. Just a few short years ago, twin vac 100psi was the standard for all portys to meet, plus the Pro 40, with it's smaller capacity tank, had an edge on vac performance.
In recent years, reading the reports on this and other forums, there are question marks over the two budget triple vacs you've mentioned. The Speedster has given most negative feedback with poor design for filling the rinse tank, generally poor reliability and awful back-up. One distributor, it has been said, withdrew the Speedster from sale because the terrible support was creating so much bad-will with his customers. However, when the Speedster is working as it should, it has a superb performance.
The Powerflite Perfect Heat with a Wonderwand is a machine I've only heard good things about. The machine has a reputation as a good reliable unit, but it's the Wonderwand that elevates it the realms of a truly high performance portable. Short of mansion houses, you'll never need to take this machine upstairs, even the now popular three story houses.
Prochem and Alltec now supply high psi twin vac machines which may be worth considering if they're in your budget.
Perhaps if you were to supply a little more info about your budget and needs, any replies could be more focused. For example, if you clean mainly residential and have no powered agitation, something like an Envirodri could vastly improve the results from your Aqua 40 and would still be of value when you trade up to a high performance portable.
Safe and happy cleaning

Ken