N54 vs N55 - which is the better tuning platform?

The eternal debate. N54 vs N55 for tuning. Heres my take after owning both:

N54 pros:

• Twin turbo, more headroom
• Can make 600hp+ on stock block
• Huge aftermarket support

N54 cons:

• Wastegate rattle
• HPFP failures
• Injector issues
• More maintenance

N55 pros:

• More reliable
• Better fuel economy
• Still makes good power (450hp+ on stock turbo)
• Cheaper to maintain

N55 cons:

• Single turbo, less headroom
• Maxes out around 500hp on stock turbo

For a daily driver, N55. For a project car, N54. What do you guys think?