All the projectors in this review have a number of things in common. All, but those mentioned in the first section, have their control panels in the back (the ones with the input section - cable connections - on the side, are the Sonys, and the JVCs).
All of these projectors have at least two HDMI inputs. All the HDMI inputs are HDMI 1.3 (support for Deep Color) except the BenQ W5000, and I believe, the Sharp XV-Z20000.
All have at least one component video input. Today we all tend to use HDMI, but for those replacing older projectors who only have component cable run, it's good to know they are still able to use their cabling.
All the projectors but one, have an analog computer input. That exception is the JVC RS10. Why it lacks it, is beyond my grasp. Perhaps it's just to differentiate it from the RS20, but omitting it is a silly thing to do. There are work arounds, but, why make us suffer. Those of us with Mac's all have HDMI, as do many PC's and PC laptops these days. Those without, will have to use a work-around if they want to hook up their PC.
Screen Triggers: Most projectors have one, some have two (two lets you raise/lower a motorized screen with one, and control an anamorphic lens sled or screen masking system with the other). Today, however, screens and sleds and masking systems can be controlled with IR or RF remotes in most cases, so screen triggers aren't critical.
RS232 (service port) All the projectors have one. This allows your projector to interface to a room control system or PC for control. In some cases, the port can be used to download firmware upgrades. Sorry, I haven't followed which can/can't do downloads, but very few manufacturers ever offer firmware downloads.