In my experience, the m pumps as far as I've ever needed it to. It's the lightest ritmo(comfortable to load on your own). It also reliably plugs in to even an extension lead with only a 1.5kw motor. It's also £4750 plus vat. I waited forever(with spunky I think??) for the L to come out. At the time I bought the Xl I definitely would have bought the ritmo l without hesitation. A lovelly machine that's quite possibly pft's best to date?? However, with tough times and the need for a machine that worked for me....as in earned money doing a variety of things(not just mono) and being supremely practical and manoeuvrable I bought the M. It blew me away. It does everything I ask of it without a hiccup. I do a lot of thin coats these days and this machine will pump with a load of hose on doing that. It will shift mono in 15m of hose after a 30min stop without problem. It doesn't trip the power or need more water than most supplies can give so no pump.
For me, the L is just more expensive(£5500) and weighs a bag of skim or so more than the M. The 45% bigger and heavier motor increases the chances of fussy consumer units tripping meaning a genny on standby(i dont even own a genny!). For an extra 5m of hose for only really mono it's not worth it to me. If mono is the main staple of your business then you'll be better off with a quicker 3 phase machine anyway.
If like me you do varied work with a bit of mono lots of EWI and texture finishes then the cheapest, most portable and competent all rounder with real world reliability and low running costs is the ritmo m IMHO.