The biggest perk of a Web 2.0 network (Something I strongly advocate) is the 'trust / authority' of the root domain. You can pump of the fake metrics on a 2.0 easier because of the root domain. Often times, the Web 2.0 of the same stats will have a weaker back link profile because of the strength of the root domain.
All things being equal, because of how easy it is for metrics to spike with Web 2.0s, the PBN Domain is stronger.
Web 2.0s have their place. Being cheap and easy, it is an excellent way to get some links on 'Aged' properties with minimal effort and works best when used with PBN links. I find they add stability to ranking myself and they can move medium / easy KWs on their own.
Different tools for different jobs. Obviously, as everyone else stated, Web 2.0s can go down and you have less control. But you have a LOT more control over a Web 2.0 than any other link source aside from a PBN and they are much stronger than anything except a good PBN domain. Use both and make your money.