I will start out by saying I have been a Jolida dealer for many years so I will not post an "opinion" rather just describe it as best I can. I hope this post is not out of line.
The JD1000 can be described as a powerful EL34 sounding amplifier. If you are familiar with the Jolida 302, you already know it's sonic characteristics but add to that more power and control. It maintains the lush, seductive nature of the 302 and in fact has the same circuitry. If you like the sound of the 302 but simply need more power, the 1000 is the way to go. It's simply a bigger brother.
Changing the tubes provides a noticable change and can be used to voice to your preference.
Not much difference in sound between the older 1000 and the new 1000RC except that the RC version looks very cool with it's glass front panel allowing viewing of the tubes with their cool orange glow.