You're probably talking about another sniper rifle, but the pistol with the scope attachment is awesome. One-kill headshots and every other regular enemy is down with two shots (again on easy). Sub machine gun takes me a whole magazine for ~3 enemies.
The shotgun is pretty bad ass but extremely low on ammo. Only use the grenade launcher thing for taking out the bigger orcs, but even they take 5 hits and it's shoting so slowly that I usually don't give a fuck about that weapon.

Funny you made a thread about that since I'm playing right now on Xbox.
It's a good game, but it definitely has its flaws.

It's basically like Gears of War without the ability to get to cover and with more melee focussed enemies.
The jetpack is awesome there, though you don't have access to it all the time (2 out of the first 8 chapters so far)

Things I don't like: It's too hard. Playing it on easy currently and already died quite a few times.
That is because the big orc enemies are too strong. They hit you once and it will drain all your shields and about 20-25% of your life. Meaning you get hit twice before your shield is up, you're dead.
That wouldn't be so bad if the character wasn't so stiff and slow. You can run away but as soon as you finished turning around, you'll likely get another hit.
Another huge flaw is that almost everything is blocking you. If you're in a tight spot and try to jump back you'll likely to get blocked by your 2 AI friends and you're probably going to die because of them.
Most enemies ignore them after a while and are instead focussing everything they have at you, which totally sucks.
Then there are rocket launcher enemies who can shot about 3 rockets at once and if you're unlucky you die in a second. Wouldn't be so bad if there was only one of them at a time, but usually about 4 or 5 at the same time.

In other words its a fun, if uninspiring (very linear and bland environments) game, but can also be a very frustrating one.
Oh and you're mostly smashing your way through the game or using pistols as they are far better than any sub machine gun so far.

It's basically like Gears of War without the ability to get to cover and with more melee focussed enemies.
The jetpack is awesome there, though you don't have access to it all the time (2 out of the first 8 chapters so far)

Things I don't like: It's too hard. Playing it on easy currently and already died quite a few times.

Sorry but it's really not that difficult.   Haven't encountered anything of what you're talking about.

On the standard mode sure there were two situations where I had to die a few times to get through but that's expected....the balance is perfect. Big encounters - enemy size and number of enemies - require you to think a little more than just stand there mashing the melee button or sit back and shoot. That's how it should be. 

yeah right it's totally not unfair when going through the sewers and suddenly a bomb squig falls from above, explodes with no time to react and drains all your shields. (Thank god the game didn't put more enemies in these parts).
Don't get me wrong everything is fine, UNTIL you face a Slugga Nob or another big orc who prefers killing you face to face. Then the game just gets incredibly unfair. You can't concentrate the fire on him, since other orcs are running at you and causing damage. You can't run away since there is not enough room to do so, you're slow as hell so it wouldn't be of any use anyway. Jumping out of the way is as I said also flawed due to basically everything blocking your path and also takes ages to perform.
If you're fury meter is full, you should be able to kill him without many troubles. If it's not full it's just pure luck.

Basically the enemy scaling has gone horrible wrong. The little ones die when you look at them, the medium sized ones die with a few sub machine shots, the big ones need 3 full magazines in their head, 5 or more of the grenades or a shitload of hits with your melee weapon.

Could've been easily resolved if there was a way to block.

I've just received a hammer which does much more damage and I haven't faced one of the bigger orcs yet, so it might get better from now on.

I've been killed by those bomb squigs twice..but each time I knew it was because I wasn't paying attention to my surroundings. That's what this game requires really, once you enter an area with some enemies swarming towards you, you need to take stock of which direction they're coming from, which enemies you're facing and which weapons will deal with them best.

Also, the health that you recover from melee is the most important consideration when fighting those big guys - you can pump them full of lead as they run towards you but just don't engage them close up unless you have full health. This means moving around the 'arena' and finding some smaller guys to melee to get your health back. (And as you said, the average/ittle orcs aren't a big threat - you can move and dodge around an arena pretty comfortably without them killing you). Roll around the big guys and then whenever they get close (or you think their health may be low enough) go in for the melee. Maybe this game just isn't your style, but considering you didn't mention anything about Gears I honestly am surprised you're having trouble with the 'weight' of the character movement. 

Anyway, that hammer and jetpack is a TON of fun - enjoy it