LX200 RA tracking problems (are they the same for 14" LX200's)

I've begun CCD imaging with a pier mounted 10" F/10 LX200 Classic.

After the anticipated (usual) problem elimination phase, one
fundamental issue remains. The RA tracking (error graph) shows random
spikes of +/- 1-4 arcsec at frequencies of 1 second or less. This
"noise" is random and happens throughout the 8 minute worm cycle, not
intermittently. I can successfully train out periodic error (manually
or with CCD), but after training, auto-guiding is worse due to the
random spikes. Even with fast exposures (0.1 sec) the guider sees the
error, but by the time correction is applied, the RA error has changed
so overcorrection often results. PEC adjustment compounds it (if PEC
is on). So far, my best images were made by stacking 1 minute unguided
frames with PEC training erased! But RA spikes still manifest (too
often) as elongated or doubled stars. Sigh!

Since I really have exhausted all other possibilities, it MUST be the
RA drive/gears of the LX200. It can't be seeing as it doesn't happen
in the Y direction. I've tried loading to east and west, and perfect
balance. I've measured error with guiding active and off (spikes in
both cases). I have perfect polar alignment and I tried all variations
of aggressiveness and calibration settings. It looks like I've got to
disassemble and clean the RA mechanism as it is the only viable cause
remaining (and this worked for others from what I've read).

I'd hoped to avoid this altogether and I'm minded to make do as I
intend(ed) to buy a 14" LX200 at the end of this year (observatory and
mount were sized for a 14" SCT – not the 10" SCT I currently own.
How's that for aperture fever "built in" :-)

So my question is – does the 14" LX200 have exactly the same
RA/guiding issues as the earlier (8", 10" and 12") models – or is the
quality better these days? I'm not so sure that I want to spend £5,500
for a bigger scope if it's likely to have exactly the same (guiding)
limitations – even if it does have twice the light grasp. Or perhaps
I've just got the wrong impression from using a second-hand (old?)
Classic LX200.

Cheers
Beats

PS. I don't want a GEM and I DO want more aperture and resolution.