Well, where are you located, what are you riding, and how fast are you?
Stock generally leaves something to be desired. Specifically, the spring rates and geometry are often not good enough to handle race track use: too much actual traction and cornering load to support some consistent chassis geometry that allows your reaction/input to work in a way that is consistent. This is NECESSARY even if you buy the most expensive suspension components available. And it is the most neglected area of club racers/track day riders. Parts are bought and installed, but the spring rates or geometry are all wrong. So, they gained "nice dampening" and "lots of adjustments", but there isn't a change in the chassis that really makes it "work right".
If you don't know how to get the bike sorted out, then working with a good local suspension guy is important. Not one that just took some class on shim stacks, but someone that has a handle on how spring rates, shock lengths, oil heights, fork heights, tire differences will all affect YOUR chassis. They may have a starting point, but it does still require some work to develop a bike.
I think Roger Penske's irritation with the rest of the suspension world is evident when he moved toward setting up Penske in the suspension business. Seems like their quality has been pretty much outstanding, including their less expensive options. Ohlins is a consideration, but I believe that at times they can make things a bit more complicated. Some items like shocks coming from some distribution with incorrectly labeled shock springs and shock springs that are shipped based upon two up riding. The internal quality of OEM shocks, in general, isn't so good. Save your money on making something out of nothing there. The other aftermarket shock opportunities out there can be enticing. Can be lower cost alternatives, but there can be some issues. Parts availability and general set up knowledge. It's not that they are bad, but one almost needs to be a bit more self sufficient and knowledgeable about set up to operate with one of the other brands.
I really haven't had a whole ton of experience with a lot of replacement cartridges as I was regularly beating most of the field with stock cartridges. A proper spring rate with proper valving, oil, and a shim stack change is probably all that is needed until you're right there trying to win expert manufacturer contingency races where one's riding is refined and half seconds count.
As of late, I've been using Trackside Engineering here in Wisconsin because of the products and experience they have. Over the years, I've used suspension guys from both coasts and places in between.
Should give a start...