The four most important boards in the 1250 are removable in less than 2 minutes (both drivers, protection, and regulator); the 9000 has easily removed driver boards, but that's it. On the 1250, the regulator is mounted up top in a vertical position for good cooling; on the 9000, the regulator is part of the protection board and is hidden underneath the unit, mounted horizontally, where it is forced to bake itself, and is not easily accessed for service, and (for all practical purposes) is not removable. The four large power supply caps in the 1250 are easily replaced with any number of devices available from a dozen or more manufacturers; the 9000, with the oval caps, requires that the unit either be converted to eight individual capacitors (ala the G-8000), or the oval caps disassembled and stuffed. The switches in the SX-1250 are moderately easy to clean and stay that way for a long time; the 9000 are a pain to clean and seem to be orders of magnitude more troublesome than the 1250 (or even most other receivers). The 1250's power output transistor heatsinks are huge compared to the 9000, and allow simple and easy access to the devices themselves; the 9000 has that heatsink backplate that must be removed to gain access to the power output transistors, and it's always a motherf%#king mess, with heatsink grease everywhere, and that finned backplate always makes half-assed contact with the transistor mounting surface (you can see the contact pattern by cleaning the plate and applying new grease...mount, remove, and examine). The bias circuitry of the 1250 is properly compensated with the STV diode in direct contact with the power transistor heatsink; the 9000 has no bias compensation in contact with the power transistor heatsink at all...bias compensation follows the temp of the driver transistors, which is a big compromise, and increases the risk of thermal runaway.
One thing that Sansui did right was its use of three relays on the protect board...one for each speaker set (nice Omron LY-2 types), and another 4PDT for the headphones and the protect lights. The speaker relays are switched from the front panel switches, whereas the 1250 passes the full current of the amplifier output through the speaker switches and through a single 4PDT Omron relay that is, IMHO, barely up to the task.
There's more, but I'll let it go at that. Understand that these are both two of my favorite receivers, but you're comparing the G-9000 to 'The King', so you'd have to expect a few knocks here and there.
