VNAV on the embraer is great - you fly an ILS from 120 nm!
The problem is that some people think that your genitals shrink if you use the speed brake, and when the machine bugs back to 250 at about 15-16000 ft they intervene not realising that the machine might bug 250 but it knows that it won't slow down to 250 until about 10 grand.
People try and fly it like a 737 in our outfit and build level decel segments and wonder why it doesn't work properly. They dance over the guidance panel like they get points for button pushing, when in reality it will do a terrific job if they just left it alone to do its thing.