ericL wrote:No synth capabilities, only samples.
No mod wheel or pitch bend on board.
No aftertouch.
No morphing and limited MIDI controller capabilities.
One half of the sound engines.
Probably a few others. If you can live without the above, the Electro 6 can play the same piano sounds, most of the same samples, and comparable organ engine.
(some of the few others)
One half of the Effects and without independent Amount control (only Rate + 2 Depth levels on FX2 only)
Rotary and Compression are not independent but part of AmpSim (Spkr/Comp) FX
No Out 3/4 (with per-Section routing)
No separate CtrlPedal and SwellPedal
(and I am sure I am still missing some...)
On the other hand there are also some pluses on NE6, mainly the Seamless Transition, which can partially compensate having less sections + physical drawbars (if you miss them on NS2)
Bottom line for me the answer is "no, not so much comparable" but, as also ericL said, it may be sufficient if you just use NS2 in a "relatively limited" way and so you can live with NE6 "reduced" features (just look at them as they are, not making any comparison, imagine you have no keyboard and you want to buy a NE6 and see if it would fit your needs)
PS: I made a similar transition, NS2 SW73 -> NE6D 73, initially it felt sufficient but it didn't last long, finally I went back to a NS (but this time a NS3) because I realized I needed the NS features and flexibility, but YMMV