There have been several Firmware updates to the A77.. not sure where you get the idea that Sony is not big on them. The made some IQ improvements from what I read.. Fixed some Bugs and created some settings.
You can't fix the noise from the sensor with firmware. The A100 was 10 MP the A77 is 24 MP. The per pixel noise will be higher.. if you don't over process the images when they are printed or scaled for screen usage the noise you see from what is an extreme magnification will be reduced or removed.
As to JPGs there are a number of settings for JPGS in the camera.
- You can turn the noise reduction up and down
- You can also turn the sharpness up and down..
No firmware update need, just some more time with a good book like Gary Friedman's A77 guide.
http://friedmanarchives.com/alpha77/
If you don't like the JPG look.. learn what controls the camera has to customize them..
Enjoy the camera it is pretty great..