Ob shafts
I have a 1st gen. OB Classic Pro shaft and an OB1+ and a OB+Pro.
I don't really feel any difference between the 1st gen. OB and the + generation (comparing my two Pro shafts). The new shafts look nicer (as noted above), but I can't say they play noticeably better.
The big difference in OB shafts is between the ones with the wood ferrules vs. the ones with the plastic ferrules. The wood ferrule shafts (the OB 1 and OB 2) have a softer, quieter hit. The plastic ferrule shafts are stiffer and have a crisper hit. (This is true for both the first generation and the + generation.) Comparing my Ob1+ to either of my Pro shafts, the difference is real and very noticeable. But comparing my two Pro shafts, there is not much of a difference.
Originally, OB offered only the OB1 and OB2, both of which had wooden ferrules and soft hits. Later they added the Classic and the Pro, which had plastic ferrules and firmer hits. All of these were first generations shafts. The Plus shafts are the only second generation shafts. But the rule is the same for both generations: wood ferrules soft hit, plastic ferrules harder hit.
So the big decision you need to make is which kind of hit you prefer.
If it were me, switching to OB for the first time, I would go ahead and buy the cheaper first gen. But I think that whichever way you go you will be happy with your OB shaft (at least I am).