[I think you meant
55-250, so I'll go with that
]
I've been using this lens for around six weeks with my new 40D. I should point out it's my first DSLR and my first tele lens, so this is coming from a fairly inexperienced user
Having said that, I'm mightily impressed. It came with a kit I got from Hong Kong (along with the 18-55mm IS). Focussing is perhaps a little ploddy sometimes, but the range makes up for that. In good light, you can get amazing pictures even at 250mm. I took a robin a few weeks back (pics in
this thread. Make up your own mind but I felt that for the price, size and versatility, it's a darn good lens.
Hope that helps