I would consider West Fork a substantial step up from Bear Creak and more continuous and technical than Black Rock. I think of it as a half step up from SSV because it is enclosed, removed from the road, and more continuous. If you run it clean, the run is a blast. If you screw up, you can have a pretty bad day. I really enjoy the run but always take it seriously (i.e. class V).
The entry falls are the easiest part of the run and a lot of fun. 1st Z Gorge is challenging but pretty straigh forward. The 2nd Z Gorge is more challenging and the consequences step up. If you choose to do the 1st Gorge you have one small river right eddy if you want to avoid doing the 2nd Gorge.
The class v "boogie" water below the Gorges can be technical, continuous and moves come up quickly. I've seen many boaters get pinned up in the rocks here. Most of this is not reasonably scoutable. Heads up for the las major rapid.
The hardest rapid on the run is Gun Shot. This can be scouted from your vehicle by hiking down from where the power lines cross the road. It is not currently runnable and has not been runnable the past 2 years because of serious wood in the entry. You can put in river left just below the wood and run the rest of the rapid. Warning: this rapid comes up crazy fast and eddies are few. Plan your eddy, know your eddy, make your eddy or....
Final recommendation: Scout all the drops prior to running the creek (even if others in your party have run it before). You will be happy later. And, unless you are a strong class V boater, I would probably not do my first run at 250 cfs (below 200 and down to 150 is a good first time level). If you like that, add water