Product review (5 stars): My First One Lasted 9 Years Beyond the Warranty - Bought a Second One
I would absolutely recommend the Acme Miami DryerJet - Vent Booster.  We purchased the first one 10 years ago.  We originally bought a vent booster, because, with the elbows and length of pipe totalled up, we were running about 25 feet to the outside vent hood.  The booster did the trick and cut drying time, and helped keep the pipe from building up with lint, too.  We bought from this company because it was the only one i could find in my price range at the time that seemed sturdy enough.  When we got to the 10 year mark, it started making a slight squeal noise when it first started up (begins automatically about 2 seconds after the dryer is turned on).  I took it apart, cleaned it well, lubricated what i could and reinstalled it in the line.  It was fine for another 4 months and started squealing again.

I called the company to see if it might be a loose fan blade that i could replace.  they said, "It's probably just worn out.  you've already used it 9 years past it's warranty period." (which is one year...warranty).  We just had a new dryer installed and wanted to make sure we got the same great performance as our older dryer. I used this same vent booster, even though i originally looked at some other models, because the other one just "worked." It was a great purchase for us.  Another reason was that i already had the pipe configured for it, so it was as easy as in and out...no reconfiguring my pipe.

Having said that, and knowing what i know... i would have reconfigured it any way to fit the unit if i had to.  it's a top recommendation from me.  Worked the first time, automatically on and off.  Our older one had started getting a little noisy as we got to the 8 and 9 year period, but being above the dryer, it was really just competing with the dryer noise.  The new one is pleasantly quiet.

Thanks Acme Miami for a great product.