Re-fitte my Yamaha shock to trade the S10 in, my memory was...
..The OE shock was pretty good solo, giving a slightly soft but nicely compliant ride - generally pretty good.
I then fitted a Wilburs and as I was doing a lot of two-up went up to a 150 spring, this was a good compromise, massively improved two-up (but still not perfect) and better in many ways solo, it was on the sporty side of firm, but due to much better damping and a wide adjustment range. Once the Mrs got her own bike I went down to a 140 spring on the Wilburs, still a fair bit firmer than stock but now about perfect for me.
Re-fitting the OE shock after 4 years my memory told me it would be quite good, a shade soft but with a nicely controlled ride - not quite the case, after four years on the better suspension the rose tint was exposed as soon as I rode off, sure it was a shade softer but it seemed to buck more over bumps and not settle anywhere near as quickly as the Wlburs, not saying it was bad or terrible, but after getting used to a much better quality unit the swap back down was very noticeable.
I then hopped on my new KTM with its WP suspension and right away could feel the extra quality - especially up front where I now no longer get a sudden jolt from hitting small bumps at speed.
I think unless something is very bad you just adapt to it, ignorance can be bliss as once you try that bike with the Ohlins / WP / Wilburs etc on it you have far less desire to start spending, but when you do I still think it is worth every penny.