Some love their PDS-equipped bikes..I'm not a fan, they inherently lack the versatility of a linkage bike.
I think you mean twin chamber forks vs open, technically they are all cartridge forks. The TC forks do offer an advantage during higher-suspension speeds and are more versatile IMO, but the OC forks are fine for the non-racer.
Oil injection would be one of the first things to go if I bought a new Beta with it. Some people love it, but it's not a high-quality system and offers no real performance advantage.
All the Beta's come pretty much set-up for dual sporting...they already have the wiring run for turn signals, just need the signals themselves and a flasher.
The Beta is a wide-ratio gearbox, but isn't gappy like the old xc-w's were with the 5 speed. I occasionally race mine and am at no disadvantage because of the transmission.
The bike is pretty lightweight. Not quite new Ktm weight, but it carries it well and I'm betting will be a more solid bike in the long run.