someone on svrider was asking for an opinion on zx or gsrxr shocks.. As with all suspension questions, the response is along the lines of "depends on your expectations?"
Wall of text follows:
The main thing to understand about suspension, is it very much depends on what you're doing with it. A slow street guy is going to have a different set of demands than a fast street guy, yet different from a beginner/intermediate track day rider, and drastically different from an expert racer. Your suspension can only be 2 things: good enough for what you're doing, and not good.
take front spring rate for example (it's one simple number and it's easy to explain).
at 170lbs, for street I should probably be on .85 springs. For track day or very aggressive street .9. There are 170lb racers running 1.05. Put those guys on my street legs and they'll have a hell of a time getting the bike to ride the way they want to. {ut them on my track bike, and they'll have a better time, but still feel like they set themselves back a few years. Put me on that 1.05 and i may as well stick a piece of wood in there whether i'm on the street or track. I'm not good enough to make any kind of use out of that stiff of a front. Eventually as I get faster, incrementally i'll grow up to that spring rate.
same is true for shocks. a new rider with a $1500 ohlins triple won't be able to make use of it or process the feedback from the bike that tells him whether it's doing what it needs to. It's only really possible to comprehend suspension in terms of "better than before" or "worse than before" at your skillset. As you get better the needs change, and the progression of both processing feedback and comparing settings gets more precise.
the 4 components that are all inter-related you're trying to reconcile are
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your needs
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spring rate
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valving
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settings
any suspension option you get, you can ruin by getting one of those 4 wrong. And any suspension that you get right, or even really really right, will only be right for that space and time. Your needs change, your weight changes, as your speeds change the spring rate and valving may change.
all that said, for a street 2g, springs and emulators and an ohlins su323 with the correct spring is more than enough. a gsxr or zxwhatever rear swap is almost always better than stock (except when it's oversprung to hell for you), but not as good as the "cheap" ohlins. the adjustability will also only take you so far especially if you only have so much ability to interpret the feedback.
no holds barred, i'd be on valved ak20s or equivalent and a penske triple. that would take me the rest of my life to outride on the track. and would probably suck as a street setup.