A lot of people swear by their E2, no matter what. Of course, there's tons of stuff the 6 can do that the 2 can't. But *IF* the 2 can do what you need, people like its simplicity, it's often said to have the best clav, and some people think some of its other sounds are better than in newer incarnations as well. There's always subjectivity to that, though.
Gambold wrote:I think it was cphollis who suggested that it's worth taking a look at every other update - as in, if you owned an Electro 4, you could skip the Electro 5, but once the 6 came out, it warranted consideration.
I recognize it's basically a way of saying, with changes being incremental, it can be more cost-effective if you wait for an extra round of changes before upgrading, i.e. for there to be enough changes to warrant the cost, but I'll offer an alternate take. There's also value to having the features you'd like to have and enjoying them now, rather than waiting 3+ years for the next model... and especially in the case of Nord, when that next model could easily also remove features you like too! I think the decision of whether to update to a new model or wait for the next gen really just comes down to how much you really want the features that new model has.
Here's my quick take on what I see as most significant changes so far, sticking with the 61s for simplicity, and not counting changes to organ/Leslie engines since people always seem to argue about which ones are really better anyway...
ELECTRO 2-->3
* Gain: sample library, high quality piano library, ability to load your own samples
* Lose: you only have 2 quick patch select buttons instead of 8
ELECTRO 3-->4
* Gain: drawbars, 4 quick patch select buttons instead of 2, MIDI over USB, long release and advanced string resonance on the pianos, delay effect
ELECTRO 4-->5
* Gain: 2-sound split/layer (plus split/layer with an external sound over MIDI), informative OLED display, Set List mode, more memory, pipe organ, advanced piano string resonance, velocity curve adjustments, more envelope and velocity adjustments to sampled sounds, more effects and overdrive options, B3+bass organ mode, compatibility with enhanced EPs and the white grand piano
* Lose: clav EQ
ELECTRO 5-->6
* Gain: 3-sound split/layer with crossfade, seamless sound switching, additional pipe organ, more polyphony, more sample memory, compatibility with sample library 3, numeric pad program selection mode
* Lose: assorted tweakable organ parameters, Set List mode, ability to split with an external sound over MIDI
I guess the biggest jumps in total functionality were from the 2 to the 3, and from the 4 to the 5. But some of the other models still had very significant changes maybe you wouldn't have wanted to wait x years to get, perhaps even only to be disappointed by what disappears, too!