I've traveled on French TGV trains and German ICE trains. Both were fine, very smooth ride. I didn't bother to purchase fancier tickets as the trains are rarely full and you get plenty of space with a table in "Coach." For a few hundred miles they are great, less hassle with security and probably quicker overall.

Eventually air travel becomes a quicker (and sometimes cheaper, in the EU at least) option. I flew from Munich to Malaga for $25 or so one way. That full journey wouldn't have been possible on high speed rail and would have been very expensive using rail tickets - not to mention, time consuming.