I can only relate what I've seen with a Lifetime Ultra, and the factory software to update the firmware in the receiver
(found here) ==>
Download
I used this software to upload new firmware to my Lifetime Ultra when it did not respond right to USALS commands and a motor. I was quite nervous about the warnings concerning the warrenty, and wrecking the unit by jamming up the thing up with incompatable hardware. Had to do something, the motor just wasn't working to expectations with the relatively new release of the Ultra hardware.
I did try to work on channel editor software, but I didn't see much benefit to it since what I had was OK at the time.
The procedure was easy. Hooked up computer, XP tower clone computer running XP, 1.6Ghz pentium system with 512mb memory. Very typical system. But it did have standard serial ports. Connected the F-F cable as you describe, and make sure the factory software would read the receiver. I figured that if it could read it OK, more than half the battle was done. Used the software to find the new BIN file, and sent it to the box. Reset it with factory code (1668 I think) and it worked with my USALS motor so all was well.
Other on the forum use, and have discussed channel editor software but I've found no need to use it. Maybe thats what you're talking about - if so maybe they can chime in and talk about the how's and why's they use that. Sorting and renaming channels displayed is probably the reason - but i'll defer that to those that use that stuff to say so...
With the use of USB to serial port converts, well some ham radio software ("packet radio") software was very fussy and did not operate right using these devices. Also some radio control did not work right.
It's really hit and miss and depends on how well (or bad i guess) the software is created.
regards...