They are the same camera - other than the differences in framelines & finish. The Rollei 35 RF is essentially a special edition of the R2 retrofitted with framelines to match Rollei lenses. If the price is the same, the Rollei is the better buy because it comes with a 2-year manufacturer's warranty, deluxe camera strap, & better manual. If the prices are close, you can also use color to decide. The Bessa R2 comes in black or olive green. The Rollei 35 RF comes in silver/chrome finish - best with silver/chrome lenses while black lenses match better with the black Bessa R2.
Of course, the frameline differences between the cameras also dictate choice. Bessa R2 framelines offer the more classic selection: 35/50/75/90. Rollei has 40/50/80 framelines, designed for use with their matching lenses. With the introduction of the Voigtlander 40/1.4 Nokton, there are now a few choices available in 40mm lenses, which also include the Rollei 40/2.8 Sonnar & the Leica & Minolta 40/2 lenses (Leica/Minolta available on the used market only). Regardless, there are far more choices available in 35mm lenses than there are in 40mm lenses. Furthermore, the Rollei 80/2.8 Planar is the only 80mm lens I know of, although I have had no trouble using a 75 mm lens with the 80 mm framelines. It means that the framelines cover only about 81% of what the lens sees rather than the traditional 87% coverage.
Finally, the 40mm framelines are easier to see on the .7x magnification viewfinder shared by both the Rollei 35 RF & the Bessa R2 than are 35mm framelines. Eyeglass wearers will find this beneficial when compared with the wide angle view from either the R2, R2A, or R3A.
Unless there are preferences for any of the features mentioned above, the R2 would seem to be the better choice because it is available at Photo Village (www.photovillage.com
) for $499, while the Rollei 35 RF costs $599 at B&H and Adorama. The R2 also offers the wider range of focal lengths (35 - 90), so it is the logical lower cost alternative to more expensive rangefinder options, i.e. Leica. Photo Village seems to have the last of the R2s on the new camera market. Both the R2 & the Rollei 35 RF are out of production, so when existing stock is gone, that will be the end of the mechanical rangefinder as a new purchase option.