I have the makita, its a decent saw, have no real complaints, I have gone wayyy off heavy miter saws on site but mine sits on a
bench and yours shall too by the sound of it.
The makita has the bevel adjustment at the front which is awesome in my opininon and yes the rails are front mounted, IN THEORY this means it can be pushed back aginst the wall, in reality the dust extraction is on the rear and is a nice design (catches from both rear of and above blade into one port) but actually keeps you off the wall to fit a hose in.
the kapex 120 has a nifty feature of not only front release for bevels but also adjusting the angle via turning a front mounted knob which looks good, 60 doesnt seem to have this so i feel its a bit lacking for the money/ riding on its brothers coat tails a bit.
With most other miter saw you are fighting the weight of the motor etc whilst moving it and locking it off, not the end of the world but it is noteably easier with the makita.
personally I'd go for makita and add an aftermarket shadow line via a LED lamp kit, the dewalt system wins in this regard but I find hard use renders dewalts fairly innacurrate (picture stick framing a few houses and then some)
worth noting most saws are designed to be used right handed and this is true with makita, the 2 stage trigger has a button on the left side of handle for your thumb, the kapex looks more ambi dextrous all beit at a very uncomfortable (to me) angle for your wrist to be operated
I dont particularly like the fence on makita, it consists of a lower section circa 40mm high (permanent) and an extension that needs to be removed completely for certain cuts, other saws do similair but slide on the fence to make clearance where as these need to be lifted off and stored somewhere and once removed there isnt alot of support for tall pieces