Statement Jewellery - Yay Or Nay?

I am a huge fan of statement pieces - particularly when it comes to jewellery. I think they can add so much, so easily to a what is initially quite a plain outfit.
Recently, I've managed to find an abundance of these kind of pieces - Primark and H&M in particular, stock some amazing bits. In fact, all of the items featured here are from one of these stores. My two current favourites are the "gemstone" necklace and the wine coloured beaded/bubble necklace which is a little bit of a Day Birger et Mikkelsen rip off. For £4 each though, I think these two are perfect for adding a bit of glitz and glam to any ensemble during the Christmas period.
What does everyone else think of chunky "statement" pieces like these? Are they something exciting and a little bit different to add to an outfit, or are they a bit too much? Personally, I can't get enough of them!
Ooh P.S. For those of you who entered my big 1000 follower giveaway - the winner will be announced on Sunday so stay tuned! :)