The other difference is interface. The QSX, and other SDR-based transceivers, work like other regular transceivers. They have USB port for computer control and sound card output. Some newer radios provide I-Q input and output which can be used for more advanced modes. But the bandwidth is limited compared to the SDRs which can monitor an entire band.
The SDR sure has utility but that comes at a compromise. I've done some professional RF stuff in the past and 99% of the problems are solved with very simple and way more precise gear compared to an SDR.
Have a look at http://websdr.org and have a play around with SDRs and then go look at a video for a Yaesu or Icom "rig" and see the difference in the usability. The QSX is more the Yaesu or Icom end of things.
If you can't afford it, go for the QSX! I may replace my commercial rig with one if it's any good.
Just google like any other technology. Answers are all out there. I never went to any amateur radio clubs. I paid up to do my exams, bought a radio and just wobbled into the bar like a drunk.
Also you don’t have to talk to someone past exchanging RST etc. If they start going off on one just tune away.