1. basically gen2 (2009-2011) and gen3 (2012-2016) are almost different bike in terms of body (frame, swingarm, footrest) and looks. the engine is the same, with a little bit of tweak to the ECU fuel setting and incorporated the vacuum tube mod that was pretty popular among the older gen into gen3 as standard. so called better response and torque at low end. but the diff is hardly noticeable lah. other wear and tear parts like sprocket, chain, wheels, brakes are shared and interchangeable.

2. 2012/2013 came up with valve issues because kawasaki went cost-cutting and made their valve in thailand (basically the whole bike are made in thailand factory anyway) and no longer used japan-made valves. suffice to say it caused some red-face to Kawa msia enough to issue a recall under the guise of "goodwill service" and replaced those Thai valves. however to be fair, even older gens occasionally were reported to kena valve issue too, so i'd say that apart from valve quality, rider''s riding pattern played a role too. pakai inline twin tapi pulas macam inline4 kejar superbike, mana tak hancur?

3. i was told that with aftermarket slip-on/full system exhaust, gen2 punya bass is more solid compared to gen3. i cannot verify anyway because i prefer to have earpone/earplug and no longer cared about sounds. inb4 #loudpipesavelives

4. allow me to clear up this misconception, gen2 bikes are not JAPAN CBU, no need to glorify the word CBU when it is assembled from its Thai factory, the same place where the CKD gen3 came from anyway.

5. both gens are ok in its own regard. personally i am inclined with gen2 because i have a few pretty sick mods in mind. however nowadys i have gone past the stage of tinkering with bikes plus i no longer have the financial capability to splurge on it, so given such circumstances i would pick a gen3 over gen2

6. last but not least, since paying for a used bike, just top up a little bit more and go for a used versys. it is a much comfortable bike in terms of daily runs and touring purpose.  plus it has bigger presence compared to er6n and wont look awkward with boxes. but that's just my biased opinion as an ex-owner of a versys lah.