It is quite useless to consider cfms with a recirculating fan as NOTHING gets vented. External venting is always the preferred option, especially if you intend to use any one of these ranges at maximum capacity.

Well, a recirculating hood would be safe to use but it won't do a great job removing heat, smoke, odors, etc. Even on an interior wall, it may be possible to run a duct up to the roof or through the ceiling to an oustide wall - that would be the best thing to do.

I've had the DCS 30" range for nearly 10 years now and am very pleased as are several other people on this forum.

In the not too distant past, building codes didn't have any requirements for external ventilation, but more recently various communities have been adding such requirements, as well as requirements for make-up air above certain CFM levels, particularly for pro-style ranges. You need to check this out.