If it is in your operation or you need a modified saw to make up slack, you all need some serious help.
You shouldn't generalise with comments like "your operation". There are many different professional use scenarios involving chainsaws far different to what you're used to.
Mods are for homeowners and cookie cutters. Pros?? Please, don’t kid yourself.
You need to get out more. I'd bet my left nut that nobody around you uses modified saws because nobody around you has had the chance to. Guys like Simon, Tree Sling'r, Brad, Eric Copsey etc etc make money selling modified saws to professional users.
OK, don’t look now but you did not answer the question fully. Your answer concerning modified saws is speculative at best and you have given no cost vs. profit data. Yup, them saws go like stink and everybody loves em, is great for the homeowner but businesses work in real numbers. Any other pros have some real data to work on??
If I could scan about 50 pages of my notebook where I've logged over 8,000 trees comparing the same saw stock to modified you'd get a surprise. The numbers of trees per hour I felled went up around 20%. If you're not familiar with the work I do it is simple felling/dropping with some limbing at ground level. Anywhere up to 130 trees an hour on 18" or less or 520 odd trees a day ranging from 12" to 42" diameter. Over 8,000 odd trees my average felling speed was 37.5 trees per hour. Up from around 33 trees per hour with a stock saw to high 30's/low 40's with a modded saw of the same model. The speed increase came on the larger trees where the modified saw pulled a 32" bar with full comp WAY faster than a stock saw could pull the same bar with skip.
Most loggers and tree crews I've met still get their saws serviced by the local dealer, even down to simple things like changing a rim sprocket. Not the sort of IQ level that I'd think would even know what a modified saw was.
The other thing not mentioned here is weight and balance vs. power - why would you run for instance a stock 660 when a modified 460 will outcut it and prove just as reliable in a work scenario? How many loggers ever actually wear a saw out instead of just wrecking it?
I hold absolutely nothing against operators running stock saws, in fact I actually enjoy running the odd stock saw like my 200T (they don't run like a stock saw!). What may make you laugh is that 2 years ago or thereabouts I was against modified saws too. Then I bought one (with some hesitation but had some spare cash) and started running it in a paid situation. I don't like to call myself a pro, as that is putting tickets on myself and many people that call themselves "pros" are far from it, however I am paid to fell trees, both domestic and commercial, so some would call me a pro although I am not comfortable with that term.
No hard feelings with what I've said mate, it's just that I think you need to broaden your thoughts. For a pro logger felling, for example, 10-20 large, high value trees a day then I can't see the point of a modified saw, but there are situations where a faster, modified saw will pay for itself many times over. Mine was one of them and it is still ongoing.