I have old version but I use 'alt ~' instead of smoothing for a quick preview. Then just convert back to poly or CTRL Z.
agree with jsprogg, Ive been caught like that too!!!
reduce doesnt give good results Lion, depending on the complexity of the mesh. I tried it after doing what jsprogg mentioned and it turned to s**t, was a real pain.
Ive been caught with the quick smooth preview too, by accidently saving my work, same problem then, you are stuck with it.
"A Darkness at Sethanon", a book I aspire to model some of the charcters and scenes