It's almost akin to stunlock with dual casting and Impact.

Block is one of the easiest skills to level. Cook yourself a vegetable soup that regenerates 1 stamina per second and then find a high HP enemy that you can STUN BLOCK to death. It raises up your skill incredible fast that way.

To disarm your enemies with a shield bash is also a lot of fun.

I disagree (with the title), the sword and board warrior that i'm playing now is surprisingly fun. I usually avoid warriors because they're dull to play, but a with the blocking tree shield really makes a difference. Both in defense and offense. Playing a nord with the elemental defense shield perk, i can just laugh at a dragon using a frost attack. Then bash it and beat it to death with Dragonbane

My favourite character so far is my sword 'n board Imperial. In heavy armour of course. Granted, might be better to use shields in light armour because heavy armour generally kills your stamina, but you do look totally badass. My whimpy mage is constantly running away afraid, conjuring up meatshields desperately on the go. Sure he fires lightning bolts and he's probably more powerful on lower-mid levels, but I personally find it more fun running up to someone, shield raised, bashing him and running him through with my sword. It's a preference thing.

Blocking goes up quickly for me since I, well, use it all the time. Plus it helps my armour rating. Let the baddies have a few swings and if they power attack in bullit-time (get that perk), bash 'em (normally). If they don't bite you can use a power bash.

Three problems though. One, magic doesn't care about armour. But there are ways to fix this through perks, birthsigns and MR. Two, getting swarmed and surrounded is a problem and will rapidly drain you of health but that's a problem for all classes. Three, you need a lot of stamina if you're rolling with heavy armour.

Of course you could always abuse smitting but really, playing things naturally a sword+board warrior does fine. Make sure you max out on armsman though, you need the damage output as dead things can't take a swing at you.

It's a shield. It blocks. That's useful. Myself, I couldn't care less how fast the skill goes up or how powerful it is or isn't. Shields are there to stop people hitting you. And you can have some really fun one on one swordfights that last ages as you both swing and block.