Whilst people may be able to advise on reliability of some models I personally think you need to establish which is the most comfortable to use for your own particular build.
Also logic suggests to me that if these machines are for a business venture there strikes me as only one option, Petrol driven. Would be detrimental to business potential if you were unable to undertake work where there is no close access, if any, to electricity Battery power may run out during the job so that is a questionable option for a business venture.
The danger when people start to believe their own publicity is that they often fall off their own ego. At least travelling under the guise of the Pa Snip Enterprise gives me an excuse for appearing to be on another planet
ive used everything from an electric flymo on a handkercheif sized lawn to a 40 inch 15 hp rideon on a lawn that takes an hour .
personally if buying a walk behind mower its got to be self propelled, single lever height control , honda or briggs and stratton engine and light enough to lift into the van. mulching is preferreable to having to cart the clippings away.
Definitely Petrol if it's a business use. The Honda range seems to be the first choice for most serious professionals in domestic sized gardens. I would also suggest you consider a hover mower for sloping banks and under overhanging bushes - I use the Husqvarna GX560 on my allotment orchard.
I use the previous model to this, and it's a real pain for blocking when the grass is slightly wet, or a little long. I hope this newer model is better...
My Hayter Heritage 13/30 ride-on is like that, I was asked to review it once and said "when the going gets tough the tough get going, this stops". If I have to replace it I'll have to ask what the contractors use who cut next door, I once saw them do it when it was hail storming.
Even retired it is difficult to find a dry time before it grows too much so cutting damp is inevitable but if it is your business I suppose you have little choice. Started mower service during yet another wet day today after final cut on Sunday.
I put a new deck on my Honda ride-on this season. Before fitting, I painted the deck with smooth Hammerite and I polished the inside of the plastic schute with Carplan black trim wax. The difference this made was unbelieveable, better, I would say, than when the mower was new.