Not to pimp outside of the vendor area but I might be able to help with a couple of your questions.
I suspect the reason ours costs less for the fully welded version is due to our "Lazer-Fit" feature, wherein all the tubes are CNC laser notched and NC-bent, with assembly guides laser etched right onto the tubes. This makes the assembly process a lot easier and faster. We can have one of our full cages assembled and tacked together in the Jeep within 45 minutes, not including finish-welding. You don't have to spend a bunch of time grinding, notching, fitting, etc. If you buy the un-welded version, this should also translate to savings if you have a welding shop install it and pay by the hour. If you'd like to see the install procedure prior to purchasing, you can download the install instructions for the un-welded kit from its page on our website.
I won't knock the quality of the Gen-Right kit. I'll assume they use all .120 wall DOM tubing like we do (some cage manufacturers use weaker HREW).
If you have any questions about the product or installation, please give our sales department a call at 951-849-5911 or email at firstname.lastname@example.org