Are those wire wound vac hoses on the CFR in the picture? Is it a hide-a-hose?
Some years ago, I had wire wound hoses supplied with a new machine.. When the wand hit the carpet, the hose absorbed so much energy that it lost a minimum of 5 ft in length. I upgraded to a more modern smooth bore hose and the machine performed so much better. More energy was used to do the job intended ie lift water from the carpet and move it away.
It has also been well discussed that as hide-a-hose assemblies age, bits of fluff and fibre can becaome entangled internally between solution and vac hose, again restricting airflow and absorbing energy.
IMO, an upgrade from wire wound to smooth bore hose will give you a performance benefit, more so with older hoses. The solution hose can still be used as you can disassemble and remove from the old vac hose. Before you buy, why not borrow from a colleague? I've loaned a 50' length to a colleague to use on his Steampro, and he reckons that it outperforms his 25ft of wire wound
Maximum benefit is gained from an in-line vac when it is placed closer to the wand, not the machine.
Are the CFR two stage vacs a different spec to run of the mill two stagers? If used with a Wonderwand, these two vacs would probably be as good as three stagers. The only significant benefit of the three stagers would possibly be a little longer length, I think 130ft has been mentioned as opposed to about 100ft for the two's?
Safe and happy CFM's
Ken