The problem with hybrid builds is that while
is a nice pick, it's not really a hybrid pick, it's a light AD+AS boost on top of some fantastic burst, and you get some extra Health, Mana, AP and crit along the ride.
Trinity force is a solid item for most champs who would consider a hybrid build though.
The real problem lies with the other AD+AP items.
Is kinda great on the champs who can use it, even better after it was upgraded to 80 AP. The only real problem (aside from how few characters really benefit well from the spellvamp) is that if you benefit from the Lifesteal, you'd probably rather build BotRK out of your cutlass.
Is fantastic, but situational, it takes time to stack up and doesn't really give all that much interesting benefits until you can proc the unique passive.
If you want AP and AS, with a boost to your Autoattacks then you've got Nashor's Tooth to do the job more stably, and with better scaling.
If you want AP, AD, Lifesteal and Spellvamp then Gunblade gives you a nice active to go along with stably availible sustain.
In general, when building hybrid, it doesn't always feel like you're getting enough out of it, except for Triforce, which gives you everything and then some extra bonus stuff you don't really need.