I've just pulled the trigger on a base RT. The actual shock is the same and adjustable with an air line/foot pump on the RT. The only difference is I believe it is automatically/remotely adjustable. As far as I'm concerned, once you have it set to your preference, you'll never really use it, unless you're continually switching from one up to two up (with a heavy pillion) or hauling trailers.
It's basically like a preload, once set I've never really altered them on my motorbikes. You can add the module at any time and I doubt its too difficult to hook up yourself.
I'd be interested to know how many of those with the compressor have adjusted them via the switch, or does it automatically adjust the rear depending on weight?
That said, if I could get the RT-S in black in the UK, I would have gone for one. This RT is not my first choice but because we are buying two, a pair of RT-S in the wrong colour for us, is too much expense as the difference is doubled. I also think we'll lose less on the RT, which is this best value of them all in my book as the spec is still very generous and used buyers won't be poring over a sales brochure reminding themselves of the differences.
Regards
Nito