A lot of people seem to have hated it too, so it's at best been divisive.
I found Euros incredibly tiresome and hammy as a character too. Just a collection of cliche eeeviill psycho ticks and head tilts, packaged unsubtly in a "scary" Ring homage. Yawn.
The ending was terrible, obviously, but I didn't even find the set up it compelling, it was just a series of contrived, largely stand alone set pieces designed to appeal every sub set of Sherlock fans, cynically resolved in the most predictable, undramatic way; OMG, John has to kill someone!?" (No he doesn't) "OMG, he told Molly he loves her!!" (Who cares?) OMG, Moriarty's alive!" (No he isn't) "OMG, he has to chose between Mycroft and John" (No he doesn't.)
There were the occasional snippets of good dialogue and acting, but that's the minimum I expect from it. It was ramshackle mastabatory sound and fury, signifying almost nothing.
The AV club have it largely spot on.. though I'd even quibble with the few things they liked (why is Sian Brooke so great exactly? She's a walking villain cliche complete with silly costume)
http://www.avclub.com/tvclub/frustrating-brilliant-sherlock-stays-frustrating-r-248468