Need to know which are useful, which are bad, and which ones might be bugged.

First time playing a sword and board character, so far I've gotten Deflect Arrows and Power Bash. I got Quick Reflexes but I quickly reloaded an old save because it seems like a very annoying perk rather than a fun one like Archery's.

I also know some perks are bugged somewhat, so I'd like some info on which ones those are as well as which perks might be useless before I go spending my points.

All the block perks are great for a shield and weapon character.
For a two handed weapon character you can only really benefit from the bashing perks.
For any character you only really need one perk in shield wall.

That said,last time I had the quick reflexes perk it would sometimes gitch and stay stuck in the slow time zone until the enemy was dead.That was kind of annoying and made the game too easy when it happened.
When it worked the way it was intended it was awseome though.

Oops double post.

My last character focused on heavy armor and shields and I found all of the block perks useful - although quick reflexes did get old quickly. Shield charge is hilariously entertaining, although perhaps a bit overpowered.

Shield Charge is hella OP. It's fun as hell knocking things off cliffs with it though. It's the best option when there's a group of bandits ahead and some are firing arrows. Just plow through all of them. Or in narrow corridors when you don't even have to steer.

Hell yeah, I just wish you could use that perk on 2H weapons. Anyone know if quick reflexes work on 2H weapons?

Yes quick reflexes does work with two handed weapons.

Awesome, thanks! I can see that really coming in handy.

http://www.youtube.com/watch?v=DOKgNkufZAI is a very good, thorough guide on blocking.

The entire left side of the Block perk tree is useful, though Shield Charge will only work for a limited time, and this bug has yet to be addressed in a patch. The Deflect Arrows perk will still occasionally not work as it should. Strangely, the Power Bash and Deadly Bash perks actually work better for weapons (which is described in the aforementioned video). Putting five points in Shield Wall is only needed if you aren't going to enchant gear with fortify block, and the numbers listed are wrong (the numbers actually are blocking is 10%, 20%, 30%, 40%, and 50% more effective). The Quick Reflexes perk sometimes will keep the game in slow-mo until the enemy dies/a previous save is loaded, so be wary. Also, if you have the Block Runner perk and hold down block with a shield/dagger while in sneak mode, you will move much faster.

As a sidenote, bashing with your shield is a faster way of leveling that skill. You can use stamina potions or cook vegetable soup (Cabbage + Potato + Leek + Tomato = infinite bashes) to make leveling the block skill go much faster.

Personally i really like the one who gives 50% elemental protection, have saved me countless times.