I don't know about any of you, but I have always have a pretty low opinion of the Vice Admirals. None of them really showed off their power, and after Ronse and Lacroix got owned at Marineford, I assumed that all of them (minus Garp, of course) were a few significant levels below the admirals. But the Punk Hazard Arc and the revelation that all Vice Admirals have haki made me reconsider.
Let's look at Vergo first. He was able to match Sanji on equal terms, even breaking his leg, and was able to take hits from Sanji (in Diable Jambe), Smoker, and Law without showing any real damage. The fact that Doflamingo trusts him to be able to take out Law whenever he wants is impressive as well (I also think that Doflamingo holds him over Caesar, which is impressive considering Caesar's single-handed victory over half the Straw Hats, Smoker, and Tashigi). Shichibukai, despite having wildly fluctuating power levels, are generally extremely powerful. The fact that Vergo is able to take one on without much worry is awesome. Then we get Smoker. This guy fought Law without any advantages, holding him off and even pressuring the Shichibukai before being defeated. Matching Vergo can't be any mean feat either.
Now I now that some of you are thinking, well those guys are just rare cases. And what about Ronse and Lacroix? Well, let's look at some other Vice Admirals (I'll leave out Aokiji, Akainu, Borsalino, and Garp). Saul was capable of throwing warships like baseballs and ended up destroying quite a few of them. Onigumo was able to get the drop on Marco, which probably isn't easy considering the guy is a Whitebeard commander. Dalmatian, along with Momonga, was able to pretty handily take out Luffy. And if one looks at Momonga's encounter with Hancock, he is no slouch either. If push came to shove, I think that Momonga would have been able to take on Hancock at least as well as Smoker did with Law. Ronse got taken out by Whitebeard when he was in a bad mood (hell, even Akainu couldn't take that much), and Lacroix was going up against a giant among giants. Not much you can do there.
So the point is, I think that I have been underestimating Vice Admirals. For a long time, I thought that Vice Admirals were basically low-level bit players, and that the core of naval power remained in the Marines. However, if you consider that there are about 15 Vice Admirals who can cause problems for the Shichibukai, then the Marines start to look a lot stronger. If you look at it this way, you can see why the Marines were able to control the seas a little better.
I wanna hear some thoughts about this, as I think there are multiple angles that this issue can be attacked from. Get commenting.