A bit of a deviation from the usual Snapshot, this one is an early look at 1.5.1 - which contains a number of fixes and tweaks for 1.5 - before its release next week. What does it have?
- Ender Dragon can still grief stuff like cobblestone and chests even if the gamerule mobGriefing is set on false.
- White stitching on polygon edges / White lines or black dots between blocks
- Unable to combine enchanted books for a higher level enchant.
- Hopper doesn't try to place items from other slots if unable from first.
- Fire doesn't show on 8 layered snow and hopper
- Long scoreboard objective titles can be offset screen
- Breaking a Container with Items that is connected via a solid block with a Comparator does not update the Comparator
- Falling Block entities start visually falling from 1 block higher than they were placed
- Paintings popping out / cannot place new ones
- a few Minecraft Realms changes
These look like good bug fixes, though; I heard a lot about those "white lines." It's kinda nice that we already get to know what they're working on. I really enjoy these snapshots.
You can back up any important worlds or just start a new world that you can test out with the snapshot... Both are really easy, if you know where the files are.
I'm going to instantly upgrade to this snapshot, every block had the "stitching" for me... Sigh, well, it's fixed hopefully, haven't tested yet.
And as far as installing, just use Minecraft Version Changer. If you don't want to test, snapshots aren't for you. Getting the new stuff early, without filtering bugs first, takes the joy out of just playing the game. Besides, 1.5 hasn't even defrosted yet. Go have fun with all the new features. If the bugs really bug you that much, I suppose it's a matter of risking new and worse bugs or ignoring the ones you've got now. If you want an art gallery in the end, than you should get the snapshot. Worst that could happen (with in reason) is you'd have to switch back. But with MVC that's easy.