Why use Floatzel for this? Scizor has higher attack, is much bulkier, and has priority. Also priority pretty much kills this set and many leads either are faster or have priority moves.
Firstly, Scizor does not have Taunt, which is a major element on this set. Secondly, Bulk Up does work a LITTLE different from Swords Dance (but true, if you are looking for an Agilitypasser or Swords Dance passer then you might be better off with Scizor).
Thirdly, how does 'priority pretty much kills this set'? A common user of priority in leads is Infernape; this set runs all over it. Metagross' Bullet Punch will do hardly any damage (guess what: 18.9% - 22.4%, which is not even enough to KO Floatzel after it has used Earthquake on Floatzel the first turn, which does 63.1% - 74.4%!(and I haven't even factored in bulk up) Floatzel is surprisingly bulky!). Floatzel WILL lose against Dragonite's extremespeed though (59.9% - 70.8%).
Commonly used leads that are faster than Floatzel:
ScarfJirachi: Yes, it's true, it runs all over Floatzel. Switch to something with a scarf and that can take its attack, or you're doomed.
Aerodactyl: Raped by Aqua Jet
ScarfSmeargle: Same as Jirachi.
Azelf (only with Scarf, or if it wins the speed tie, which is a 50% chance): It is still best to Taunt it, since not ALL azelfs carry Taunt, and even if it does, you might just outspeed them. If not, well yeah, you lose. You will always lose against the scarf version.
Ninjask: lol. taunt, bulk up, baton pass
Crobat: Crobat leads are uncommon these days (#15), but yes, if you do run into one, run, run as fast as you can!
Yanmega: although you outspeed it initially, it will outspeed you the next turn due to Speed Boost (unless doesn't run that ability, in which case you easily set up on it). If it opts to attack on the first turn, then yes you do have a problem.
These are the only commonly used leads I can think of that Floatzel will lose against. Aside from ScarfJirachi, none of them are even in the top ten! I really do appreciate criticism, but I like it to be well-funded before you dismiss this set as outclassed and beaten by many leads.
The only reason to use this set is for a faster Taunt, that Scizor doesn't have. There are more effective Baton Passers in OU though, and many of them have instant Recovery (Scizor, Zapdos, Gliscor, Togekiss with Roost, Celebi with Recovery).
Aside from Gliscor, none of them have Taunt, and ALL of them will be shut down by Taunt from a faster pokemon. I am not saying these leads are worse, but they are different. Floatzel is also the only pokemon that can baton pass Bulk Up boosts, aside from Smeargle and Blaziken I think.