Cleave 3.5 vs pathfinder

[CoI]

I'm thinking of giving my players the option of either cleaving as Pathfinder, or the 3.5 version (ie. drop an enemy, get an attack against another). I was thinking you choose which you'll use before the attack, but can other wise switch whenever you want based on the situation. Has anyone done this before? I'm assuming yes, and what was your thoughts on it?

[Metal Sonic]

What I did is let the players get Cleaving Finish without Cleave as a prerequisite.

[CoI]

What about folding it into cleave? And having great cleave keep giving you attacks until you don't drop someone? Is that really overpowered?

[Helaman]

CoI wrote:

What about folding it into cleave? And having great cleave keep giving you attacks until you don't drop someone? Is that really overpowered?

I like that. Its a 3 feat tree. Power Attack, Cleave, Great cleave.

[CoI]

Anyone tried this? Just combining 3.5 and pathfinder cleaves together? How does it work in play? Because I don't see it being TOO powerful, even with me giving out power attack to anyone who makes the prerequisites. Especially if you have to choose before using it.