Canon EF 70-300mm f/4-5.6 IS USM and the new f/4-5.6L Lens of L

ddman

Has anyone owned or tried these two lenses and what is your opinion in upgrade to the new L lens (is it worth)?  Thx.

Bigpiece

如果有舊就唔駛買支新L, 又貴又重，質素又唔夠小白1來但又同價。。。唔抵！

erutuf

Used to own the old one (non-DO, non-L)
quality is "ok" if you really can't afford the 70-200,
Would prefer 70-200/4 instead (even the one without IS)
300mm side is soft. (actually around 240mm and above is soft)
300mm at 5.6 is rather hard to use unless you crank up the ISO or have very bright environment
bottom line, would not suggest the old one unless you REALLY want a long telephoto lens and any of the 70-200 L lens is out of the budget.
that's my 2 cents.