Just open up your console and install the flatmod......no soldering.
Firmware updates are installed via it's own SD card slot.
There are 2 different firmwares you can use......read only, and a read/dump version which takes a little longer to boot.
I've always just used the read/dump versions of the firmware releases (updated usually when a new dual layer game is released)......although I rarely dump games from disc thesedays, I could never be bothered with the idea of changing firmware just to save a little initial boot time
It's still expensive though I think, especially considering the console itself is now cheap (or dirt cheap if second hand).
But the good thing is that if your console dies (like the DVD drive stops working, you brick it using a softmod or whatever) you can just get another console, easily remove and install it again.