Glossy versus Matte

In the big scheme of things, this is just one tiny decision among many.  But it is the exact type of decision I struggle with when it comes to writing.

It seems that in recent months, my Print-On-Demand supplier, CreateSpace, has started to offer a matte cover finish.  When all my covers were created, a glossy finish was the only option available.  Now, however, I've got a decision to make.

Below are the covers of my various books.  All the books are in a Trade Paperback size, rather than mass market.  In mass market books I don't ever recall seeing matte finishes, but in trades, it seems to be used about half the time.

New Montage 4.png

So what to do?  Keep them all Glossy, or convert them all to Matte.  Or use a mix -- please offer your opinions.