It is definately slower. I ordered something via media mail awhile back and it took close to 4 weeks. I was in contact with the seller - I KNOW when they shipped. It was very strange. I really think USPS purposely slows it down just because it is media mail.
Another time I was the seller - it was a notebook of christmas crafts. The USPS clerk went over and over the description. I patiently disagreeded that a notebook was a BOOK ... finally I told her to open it, look at it, and reseal it in front of me. That's when she relented with a "well NEXT time... blah blah blah". What a pain in the neck. What should have been a VERY quick transaction took 15 minutes.
It was not a book and should have been mailed as parcel post.
The rate for 1 lb media mail is $1.42 and for a similar 1 lb machinable
parcel post package the postage would be between $2.81 & $3.75.
In an attempt to scam the Postal Service out of between $1.39 & $2.33
you held up the other people in line for 15 minutes?