Testing the limit on my EQ6-R -
I recently acquired an Esprit 150ED. I knew I'd be undermounting my EQ6-R with the 32lb OTA. 
Before I could think about a new mount that could handle the payload of Esprit, I wanted to experiment how EQ6-R performed with this beast.

Target - NGC 7000 - Acquired from my apartment in Bortle 8 skies in Connecticut, USA

Weight - guestimate - 44 pounds
OTA - 34lbs
Flattener + ZWO Camera + filter wheel + EAF + ASI Air + Evoguide - 10lbs

Balancing - I tried to have the best possible balance on the scope. Balancing was done after the stars were focused, to avoid any change in balance due to focuser travel. I had 3 counterweights for balancing on the RA axis. Even with 3 counterweights, I had to use the counterweight extension shaft to get a good balance. 
The Declination axis balance was tough to achieve, because it was tough to move the scope around the axis and the balance sensitive to smallest change in millimeters. 

Guiding - 
My guiding error was initially between 1.2" to 1.7" RMS (arcseconds). Then I realized that my wooden balcony was creating the vibrations. But, Once the imaging session started and I left the setup undisturbed, the guiding error seemed to be well around 0.4"-0.9" RMS. 
The star shapes looked good.

Subs - I managed to get 25 minutes of Ha and 25 minutes of Sii. Oiii data was washed out due to dew.
I was happy with the star shapes, no eggy stars due to guiding. 

Processing - Pixinsight
EZ Decon -> NoiseXterminator -> EZ SoftStretch -> EZ HDR -> Channel combination -> Add Ha in Luminance channel with LRGB Combination -> Sharpening the edges with USM + MLT -> Curves Transformation -> NoiseXterminator 

Finally, I am happy with the results and how EQ6-R performed. However, I'd still prefer not to undermount the telescope and I might be buying a CEM70 to handle to payload. 

Happy to hear your thoughts and feedback. 

Thanks,
Deepan