UP is great fun post 1.03 whereas before the patches they were one of the most boring factions.

some UP VH campaign notes:

1. Declare war on New Spain ASAP (turn 1 is good too)
2. #1 allows you to take Flanders without going to war with France
3. #1 allows you to take New Andalusia (a required province for GC)
4. Westphalia is tasty (another school there)...
5. Prepare for naval fun... fluyts are great to fight the pirates or anyone else who makes it to the trade theaters. I find, post 1.03, UP is the most interesting faction to play in terms of naval warfare. Now you have to fight for the trade theaters and protect them.
6. Try to capture (chain shot is your friend!) some galleons from the Pirates and Spanish early on. Galleons have more fire-power than fluyts and they can trade. Thus, they (along with fluyts) make great 'garrison' units for trade theaters. Note that due to the high upkeep of galleons and fluyts, Indiamen will still be your "profit rakers" as far as trade goes. Still, it's better to have a galleon guarding the trade node (along with Indiamen traders) than a fourth rate. Fourth rate does not earn its upkeep whereas the galleon/fluyt does.
7. DO NOT, keep the dockyard in Flanders! Rather switch to a trade port! Why? The Dutch are all about trading and those extra trade routes, brought by the second trade port (on the mainland) will help. As far as fluyts go, they're great fighting ships for a couple decades at least.
8. As time progresses, build a dockyard somewhere else. Cuba and Hispanola are good candidates since they both get several port slots.
9. France will attack sooner or later. The star fort inside France makes an excellent Dutch homeland defense point. French armies will break their teeth trying to retake it. If they damaged the fort too much by arty, withdraw to Flanders for a turn and let the French repair the fort for you.
10. After a few goes at their former star fort, French armies are usually toast. At that point you can either take out France (march on Paris) or keep them in game indefinitely for gameplay purpuses. I did the latter.
11. Help out your allies (English and Austrians): it makes for a fun game.
12. I did not bother about conquering India until mid-game when Marathas DOW on me (trying to take Ceylon). They were great trade partners for the first couple decades.
13. Swiss and Scottish mercenaries are great! You'll love them.

I'd like to stress another important point for a successful Dutch campaign in which French and Spanish ARE NOT wiped out (a game-play decision).

Take Gibraltar early!

A big stack of French or Spanish ships sitting on the naval artery near Portugal can effectively wipe out ALL Dutch trade (happened to me). So, the Dutch need a base there to successfully defeat French/Spanish navies and repair the war fleets. I'd suggest sending an expeditionary force to Gibraltar as soon as possible. That's what the British did anyway (for a very similar reason I think). As an additional bonus point, the Dutch gain a dockyard in Gibraltar, which helps a lot since the dockyard in Flanders should be turned into a trading harbor asap for cash flow purposes.