I originally got the 190XPROB with the 486RC2 head.
After testing it with the 450D and 70-200mm f/4 L IS, I found it to be a bit weak-although very compact.
For a few bucks more I returned it and got the 055XPROB and 488RC2 head.
Wow what a difference in size, build, & sturdiness!
This is a amazing piece of craftmanship and I don't see myself buying another for many years.
Of course, if I strike it rich, carbon fiber would be in order!
Shop around, I got my legs for $160 through Amazon.
Canon 5D2 | BG-E6 Battery Grip | Canon XSi/450D | BG-E5 Battery Grip | Canon EF 17-40 f/4L
| Canon EF-S 17-85mm f/4-5.6 IS | Canon EF 50mm f/1.8 II | Canon EF 70-200 f/4L
IS | Manfrotto 055XPROB | Manfrotto 488RC2Flickr <--Comments/Favorites welcomed