No clutch is simply where the RPM's are at the exact point where they would need to be to engage the transmission when the clutch is let out. Next time you are going down a hill and the RPM's are elevated, try holding the stick into a certain gear and listen for a "whine" while it spools up, trying to mesh into that gear.
Actually, no clutch, done correctly, is completely harmless. Of course, doing it correctly can be very difficult. My counsin's Celica was a dream, I could up- and downshift all day without ever lifting my left foot from the dead pedal. That's how alot of truck drivers I know usually shift as well. I think the syncros might actually hinder your attempts, but I'm prob'ly wrong.
With my focus, I can upshift quite well, but downshifting has been painfully noisy the couple of times I've tried it, so I don't anymore.