I've always found whether you can do this successfully (no grindy grindy) depends a lot on the individual vehicle. Some are more forgiving than others.
The ForkenSwift has no clutch, so all up/downshifts are done with revmatching & holding your tongue just right...
treb: that's an awesome Click & Clack quote.
Clutchless shifting in the ForkenSwift:
In an electric Delorean: