we are professional turquoise cabochon cutters from gem grade to stabilized to high-grade rarest of the rare. we go through soft wheels like crazy and so far the rez wheels are the best bang for your buck. in my experience, they last longer than new DP Nova wheels. the resin they use is really tough so much that they have quite a break in time for cutting turquoise but if you are an agate cutter they are good to go out of the box with minimal break in. my favorite wheels are resurfaced wheels and if you get your wheels resurfaced these are a good option because the bands are really tough even on their regular resin wheels what come with the machines, they don’t last as long as the ‘rez’ wheel but they can be continually resurfaced. brass tax, the rez wheels are great wheels for a stellar price and this is a great company that obviously cares about their products. also, to break in for medium stone hardness like turquoise i take a sharp edged agate type material and use it like a chisel and reverse cut (opposite to diving into the wheel) to 'chop off all the sharp epoxy edges. you will see them flying off when you do this. then once smoother but still really gritty i will take a rough piece of agate, like a rounded rough cortex piece, and run it back and forth for a few minutes on the wheel with lots of water on it, running of course, until i can touch the wheel without feeling like im gonna get cut. (if you only cut tough hard stones, break in is over at this point) then, i take an agate cab to it and feel if it has any 'wops' in it. to do this, hold the agate cab lightly to the wheel and feel for a 'banging' as the wheel goes round and round like a tiny hammer. if it does i will keep an agate cab on until that gets more subtle. i will only cut agate or jaspers or more durable stone on it for a few days until all 'wops' are at a minimum. then once it becomes more smooth i will take turquoise or variscite to it. a too aggressive wheel that bangs around is fine for tougher stones but a 'wop' in your wheel, although will sand correctly, can fracture or separate more fragile stone. but once they are broke in i can cut well over 1000 cabs on if before needing resurface. and that is on a over worked wheel like a 280 or a 600 8" wheel. the polishing wheels are probably double or triple that. my wife goes through the 280s on her six inch machine faster than any other grit so we are now using a rez wheel in that spot because they worked so good on my machine. and to further the point, i have bought brand new DP Nova wheels that were a mixed bag. some of which were a total garbage resin job out of the box. once i got the 'wop' out i could only cut a few hundred cabs before resurface then they were perfect. double the price to get a good wheel that will last. one thing i can say to the Cabking company, is, get rid of the magnetic switch that is the achilles heel of your machines. put a hard switch in there. all my dozen or more old machines in our shop have hard switches, they aren't gonna win any beauty contests but the work every day without a hitch. i got tired of replacing those switches and it's annoying to have to turn the machine back on every time someone turns on another machine on the same outlet and it kills the power to the cabking that now i just put a wooden stake to 'pin' the switch on button problem solved until i put a hard switch in. if i ever get to it. that seems to be the biggest complaint about the machines. just ditch that magnetic junk and hard switch it or sell a plate with a hard switch that replaces the magnetic switch so people can opt out of the magnetic switch if they want to. or maybe i can sell an aftermarket wooden 'stake' fix kit. $14.99 lol. love your machines, love your products, and love the customer service. i hope this helps.