I have done the following mods to mine & I never looked back:
1. Bob's knobs for both primary & secondary mirrors
2. Astrozap light shroud
3. Telrad +/- a right angle finderscope( RDF that came with scope is
horrible to use)
4. Counter weight( sandbags & velcro) for low objects.
5. A laser collimater for quick collimation in the dark.
Some owners also suggest:
dew shield; dew heater for secondary and powder paint the inner rings and primary mirror holding case
black
Enjoy it.Its a wonderful scope no problem since bought it in 2007.