i would concur with everything the first responder said. Cranky I love mine for satellites. I've used it since I bought in new many years ago. CAT works great but it does require a less typical null modem cable. Mine is completely unmodified and I really should buy some filters for it, but despite the filters I've worked tons of DX with it on HF. Does it compare to my Flex5000....no! But it doesn't cost that much. The only thing I could recommend more at this point would be a fully loaded Flex5000a with the 2nd RX and V/U module. It works very well for satellites with satpc32 and has the added advantage of the panadapter where you can see signals including your downlink.
As for repairs, the only repair I had to have done with my 847 was the on-off power switch. I should add that I also had a TS-2000 for a time but sold it in favor of keeping my 847 largely because of one or two features, the primary one being that unlike the 2000 the Yaesu powers your external preamps through the coax with no problems. I found that other rigs that don't offer is feature just add additional issues, though to be fair some guys prefer separating their preamps in terms of DC power.
So that's my vote, get a good 847 if you can find one. 73 Rick W2JAZ