Replace EGR with a delete pipe (eg Allard):
- no more sooty exhaust into your intake
- no more oil leaks
- slightly less restriction in your inlet
- will get a warning light all the time unless you've got quite an early PD (with earlier ECU)
- very obvious that you've modded the engine
- you'll lose your anti-shudder valve (ASV) which could mean the engine will shudder when it comes to a stop, plus in the unlikely event your turbo disintegrated and the engine starts running on it's oil, it could run away with itself and you've no way of stopping it until it revs itself to destruction.
New EGR:
- cure the oil leak
- won't cause a warning light
- no change in outside appearance
- still get sooty exhaust fumes into the inlet.
EGR blanking plate (basically you undo the exhaust pipe from the EGR, insert a blanking plate, and reassemble):
- no more sooty exhaust into your intake
- no difference to appearance
- won't fix your oil leak
- will get a permanent warning light unless you have an early ECU, or you drill a small hole in the plate to bleed a small amount of exhaust gas through.
EGR stealth pipe (basically you take an old EGR valve, block up the hole that connects to the exhaust, remove the internal butterfly flap, smooth it all out, reassemble):
- no more sooty exhaust into your intake
- no more oil leaks
- slightly less restriction in your inlet
- will get a warning light all the time unless you've got quite an early PD (with earlier ECU)
- no visible difference
- retains your anti-shudder valve
Think that sums the options up