the laws of mechanics mean that a CVT with a theoretical infinite number of gear ratios within the designed range of the transmission always exceed the efficiency of a traditional planar gear transmission (of any # of speeds even if that # was theoretically infinity). the reason why that is, is b/c as you add more gears to make it more efficient (striving for more gear ratios) you are actually adding more weight and also adding more instances of momentum reduction with each gear shift.
if the 6-speed auto transmission really is more efficient than the CVT, it means that the CVT must have had some significant deficiency that prevented it from reaching its full potential - either inadequate programming or perhaps an inefficient designs of the V-blocks. who knows.
the argument of CVT vs Planar Gear regarding serviceability is a moot point when most dealers don't even rebuilt planar gear transmissions anyways. they are refurbished by a certified manufacturer (per the vehicle manufacturer's certification program) and shipped to the dealer. once a planar gear transmission starts "going" as they say, it's already too late and the damage is done. all the fluid changes in the world won't stop the vicious cycle unless you open up the beast and replace the worn out components, clogged internal filters, etc. so there isn't much you can do with an auto trans anyways without opening it up, however they will still operate until the bitter end. you can get away with a slipping planar transmission for up to 20,000 miles if you drive mostly highway and you change your transmission fluid every 5,000 miles. not so with the CVT. when it fails it's usually instantly a dud
