Triple vacs will outperform the Excel any day.
Cleansmart also do a triple vac and Ashbys Ninja can have a 3rd vac fitted externally.
I have a Scorpion and it is excellent, and the service/backup from Solutions Cornwall is very good too.
It does not have an inbuilt heater but there are advantages to that. I dont think the Cleansmart machine at top spec has an heater, but the Altec does but it cuts out when all 3 vacs are running - only so much you can do with 2 mains cables.