I think _that_ is a bit of a sweeping generalisation though - just because R1 discs don't have the extras rated doesn't in and of itself cause the quality of the discs to be higher. It is from time to time the case that the R2 will have fewer extras than the R1 (unfortunately this often seems to happen on higher profile discs - The Matrix is the first one that springs to mind) but there are equal numbers of R2 discs that are better than R1 in terms of extras.
Each of the regions has it's star discs - some discs are the same all over, some aren't. Matrix for example - although the R1 is better than the R2 because of the extra content, the best version of the disc is actually to be had from Australia which has better picture quality of PAL, combined with all the extras.
On the subject of picture quality I would have to fall on the side of R2/PAL for the vast majority of cases, although the gap is closing of late. In the earlier days of DVD support for anamorphic transfers on region one discs was nowhere near the levels it is now, wiht Fox, Paramount, Buena Vista and many others not even providing anamorphic for their best films. In region two however anamorphic has got much greater support (because more of us have widescreen TVs here, and so more of us can take advantage of the extra resolution) - this has lead to scores of discs which are anamorphic here and not in R1.
Having said all that, as CarlP says, it is dependant on a number of factors - but the rule of thumb is usually that if a clean high-def master exists of a film (as most special editions coming out now have - Jaws, MIB, Jurrassic Park, all new films) then the PAL downconversion will look better than the NTSC downconversion.
Phew! That's a long reply.