I like Mintcoin but I downloaded the wallet for windows and it would take almost a day to download for 6 months of a Blockchain. I wouldn't say this issue would have to do with the Blockchain size, more that the GUI needs improvement in how it connects and downloads the chain from other nodes. Something I have found quite useful when wanting to quickly sync a Blockchain is to have someone on the longest chain make a copy and publish it to Megaupload or Dropbox where you can download a 600-700MB Blockchain in about 20 minutes so you end up only needing to finish the last 1-2% of the Blockchain (you would need to test the security of this if you do this but you need to atleast change your RPC username and password). I have also been toying with the idea of how you could use Torrents to download the Blockchain in a spactical manner.

What some coins have also done in the past is swaps to a different Blockchain through an automated process and start from scratch once again. If you took it in terms of swapping for exactly the same thing, it would prune off all the excess Blockchain bloat and you can quickly sync again so then it stands to reason that it could become a piece of the Blockchain and regulate it's size.