I also have the same combo ( except the more robust JR 8611 Digital servos) in my 35% Carden Cap and fortunately, no jitters -even in low power mode. Perhaps it's because of the " premium" JR Digitals ?
I had read that the Airtronics Digitals are quite good, but never tried them.
I paused ; thinking that the cheap price, even less than some "sport" digitals, might mean lower quality.
No knock against them because several guys I know are using them with great results.