I must admit your info on your requirements has been spotty. As far as I understand you want a pro saw in the same range.
My next question is, what for?
The 590 with slight modifications, that anyone who can use a screwdriver should be able to perform, will catch up quickly to the pack of top performers! If I have money to waste ok, why not buy a few more pro saws in the same size class, that makes it easier on the job, no more time wasted by refueling or resharpening...
What will your requirements REALLY be?
Do you need a lighter smaller saw for quicker ground work?
=> I would check out the Echo 400, Dolmar 421, Stihl 241, Efco 4400, Hitachi CS40EA, Husqvarna 543
Do you need a stronger larger saw for quicker felling work?
=> I would check out the Echo 680, Dolmar 7901, Stihl 441/461, Husqvarna 372/576(or Jonsered equivalent)
Do you want to render your 590 as "spare saw for the job"?
=> 50cc class? => Echo 490/501, Dolmar 5105, Stihl 261, Hitachi CS51EA, Husqvarna 545/550(or Jonsered equivalent)
=> 60cc class? => Echo 590/600/620, Dolmar 6100, Stihl 362, Husqvarna 555/562(or Jonsered equivalent)
Last question, do you need the "feel good" attributes associated with the big names in the game that you want a "pro saw"?
If yes then get what you want and "feel good" about your purchase.
A lot of pros, that have to buy their own equipment over here in the german speaking forums, mention that at the end of the day the top pro 50/60cc saws "fabulous" speed increase is so marginal that there is about no gain. Many prefer the 545 or 555 over the 550 or 560(562).
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