I don't own one.
I'd buy two today and then kick myself 6 months from now when they were no longer available and wish I'd bought 6.
The reasons for the popularity of this saw are its size and its motor.
The size is probably the perfect size of larger saw, just large enough for 5" depth of cut, but much lighter and much easier to handle than the 16" Mak.
The motor is 15 amps, and it is strong. It is the only saw from Makita's late 1970-1980s product line to come with the 15 amp motor. Even my 16" has a 12 amp (I need to get a new one of those, too).
Amongst the framers I know, this saw has replaced the Super Square on the most sought after piece of kit...
The only direct competition is the Big Boy, which is nowhere near as good of a saw, and the mafell 14", which is pricey, but a very nice saw, although it didn't seem to me to be as maneuverable as the 13" makita. Oh yeah, and the Protool 13", which is similar to the mafell in price/maneuverability.
It will be interesting to see how this develops.
Cheers,
Whit