I'm with Peter, who says 'ignore the critics'. This is one of the few Allen movies I've yet to get around to buying. But I've seen and enjoyed it several times now. First of all it is beautifully filmed visually, capturing a very nostalgic fantasy vision of a kind of non-specific '30s era America; trilbys, trenchcoats, and sassy dames (Helen Hunt is great), but no hint of any Great Depression! Quite the contrary, this is Allen in straightforward feel-good mode.
The plot is zany, the look gorgeous, the romance predictable (but no less seductive and enjoyable for that), and the gags and one-liners flow with a relaxed fluency that puts the viewer (this one at any rate) at ease. Several Allen tropes, such as the frequently occuring use of hypnosis, and even a familiar face or two (Radio Days 'Masked Avenger' is one of Allen's insurance company buddies), add to the sense of comfortable continuity. There's a lot less angst and overt intellect than many Woody pics, but it's smart for all that, wearing its accomplishment lightly in its easy fluidity.
That the guy who made everything from Stardust Memories to Zelig could make something so in keeping with his whole oeuvre, and yet so light and easy, is all part of Woody's prolific and winning charm, to me. But I think I'll wait for the price to dip before I get my copy: I've accrued around 30 Allen movies so far, probably averaging around £5 a pop!