Contrary to popular belief, the sontaran experiment was always a two parter. Going directly on from Ark in Space, so by extension it became a six part adventure. These two would have been better combined as the Genesis of the Daleks would have been with Revenge of the Cybermen. I noticed this after someone mentioned it to me. Styres mission to Earth was a bit pointless, but then it wouldnt have been too dramatic, now would it?. Exactly why does he need to lure a Gal-Sec mission to an EMPTY planet? Since they are planning to go through Earths Solar system and not the colony worlds. It isnt a gripe at all. I have always liked the single-minded Sontarans.
As for Genesis, like others have said, wall yourselves in your city and ignore the other guys. But of course I loved seeing Davros for the second time, I had seen Destiny of the Daleks first. I thought a great design idea to get Davros and his daleks even closer subtley for the viewers would have been to make the Daleks black and silver like his chair. And yes it could have lost the Muto subplot and the rocket subplot could have been tightened up to make it a four parter. But over-all I was thoroughly creeped out by Davros's ability to turn life and death into a simple dinner time discussion. "Yes I would do it, that power would set me up amongst the Gods!"