Well, as much as I appreciate that FleetMac refers to my TL here, I'm afraid it doesn't meet the criteria. The Stadtholderate, after all, gets abolished in The Lights of Liberty. Most "succesful Patriotic revolution" TLs will have that issue, so I'd suggest going back to Johan van Oldenbarnevelt. The conflict between the Prinsgezinden (supporters of the prince of Orange, generally centralist and religiously conservative) and the Staatsgezinden (supporters of the sovereignty of the provinces, generally decentralist and religiously tolerant) really determined the later lines of division anyway.
So instead of prince Maurits winning that conflict and having Oldenbarnevelt executed, have Oldenbarnevelt succeed, or have them reach a compromise. Either way, Maurits is still popular so he's not likely to get deposed. Instead, the Republic would remain firmly decentralist, with the Provincial States (assemblies) sending representatives to the States-General, and those representatives having no mandate to act without the Provinces' approval. The Stadtholder would be limited in his powers, and the Raadspensionaris (Oldenbarnevelt, in this case) would be like a powerful prime minister.
If Oldenbarnevelt wins, expect the national army to be reduced in size, and provincial armies and militias to be established. The Republic is also likely to be more religiously tolerant, with full political rights for dissenting Protestants (but not for Catholics; the Patriots advocated that 170 years later, but the early 17th century is too early for that kind of tolerance).