Depends on what you want and need. I actually preferred the Sigma's UI, since you don't have to do the whole two-button push thing like on the Metz 48, which you have to do a lot to change certain settings.
I've actually found that most/all of the features the 48 has, the Sigma is capable of, and then some (like stroboscopic mode, for example). One thing I definitely liked about the Metz 48 is that it didn't lock the flash head for tilt/swivel in both axis's like the Sigma, had a better af-assist beam, and I think it went down to a lower power level in manual.
Last edited by Eruditass; 11-25-2010 at 02:07 AM.