We have cleaned loads of cinemas and always LM clean if you have access to such a system use it over extraction the end product is the same on such heavy footfall carpet but with out the dangers of split seams, odours and other associated problems you may inherit.Also its agreat sales tool, you can tell the Manager the cinema will be available for immediate access after cleaning.
I would use a rotary with Charly pads and M-power for speed if not DF or Texatherm.
Have you agreed payment terms? Cinema chains are notoriously bad payers we once waited 6 months for payment, I would get this confirmed before commencing the work.
We have also cleaned the seats in cinemas the largest being 3000 or so, now if you really want a soul destroying back breaking job this is the one.Much better to secure the work and sub it out.
On the subject once on a visit to inspect some damaged carpets at the Print Works in Manchester I watched as the carpet cleaners turned up to clean the first floor foyer carpets. In about 5 minutes I realised why I was there inspecting, I have to say it was hillarious watching these muppets attempt to work the machinery as they first flooded the carpet with water and then tried to extract without the vacs turned on
As they pushed and pulled the water around the carpet I could bear it no more and went over and switched the vacs on for them, then walked away headshaking as they struggled to pull the wands across the carpet. Quality.
The Manager informed me later that the foyer took 2 days to dry and the smell lingered for more than a week but guess what, the main contractor was kept on because as part of the overall package the carpet cleaning cost just .50p a sq mt. this is what we are up against as carpets are,in some quarters, just not considered a priority.