I like to use this- level 46, on NM act 3 almost at Mahgda. I find the plague bolas dominate everything, and frost elemental arrow slows fast packs, and is extremely easy to spam due to the very low cost. I'm at about 1800 dps, 6k health.
To be honest I still switch my abilities around alot- it seems like almost everything we have is amazing at least with one rune choice.
I think we also have a good amount of choice- I enjoy having vault and SS alot, but until act 3 I hadn't used SS at all, and don't find it necessary though from what people are saying, it might be good to get used to it for Hell when SS starts to be needed.
Most of the time using just vault I can avoid most boss and elite mob attacks unless they're very fast- generally the burrowers/leapers can be rough, or if there's no room to kite. SS though does make it substantially easier to kite almost anything- and if you add preparation (I prefer the rune that gives a gradual renewal over time) you can keep SS or vaulting for a good while.
SS will be even easier to keep up with the passive that makes your crit increase plus the passive that restores discipline on crits- I like what I have now just for the sake of heavy damage.
Spike traps I'm finding have gone from absolutely amazing in early NM and through normal to a bit more meh- enemies are way too fast, and the only traps I get off tend to be the set up ones- they can do some decent damage but they're so much harder to aim for not much more pay off than a considerably easier to use elemental arrow spam.
Rain of vengeance with demon bombers is awesome for when you're swarmed- they decimate entire rooms, and cost no hate.
I love the ice arrow- it slows, aoes, and hits very hard. I think it goes well with poison bolas. My other favourite one to go with is overpenetration rune on impale- large damage and hits everything in a line, but that leaves me with no slows so the bolas don't work as well- cluster grenades I find can be nice simply because they hit a wide range, but they are awful at short range and don't do too much damage (I find all other grenades are a mix of too inaccurate and slow)- hungering arrow is too linear to put with a straight line secondary (it's a good one if you don't like bolas though to put with frost arrow).
My favourite to mix with impale is entangling shot- yes, it does worse damage, but it's an aoe slow that gives you hatred. I find that every rune except for the shocking one is great for it- you can choose between having 4 targets for more aoe (my favourite), having a longer slow (if you find you will spend several seconds doing other things than your hate building move this is nice), or double hate building if you just wanna slow your enemy while you get ready for the big abilities.
All in all, NM is challenging enough that you have to play well- but not so unforgiving that you can't play around with many builds that aren't optimal but are a lot of fun- and you may not be able to do that so much in Hell.
I do find the DH, with just vault and no prep or SS- I avoided all but 2-4 attacks on every boss but Belial until where I am (and I expect Magda will be easy to avoid too- I'll note I did use prep and SS for Belial because he was the only big boss I had any trouble on in normal... I'll also note I got all the achievements for avoiding his attacks on NM the first try by using SS, vault and prep- so if you really want a good combo- SS/prep especially is fantastic).
Elite mobs are the tricky ones- and fast ones that leap, tongue grab you (those horrible things in Act III), or burrow (also keep an eye out for fire/poison clouds). Specifically- defensive ones can be a pain BUT, if they aren't paired with great speed or something like jailer/waller, it's usually easy (though time consuming) to just kite kill them. For actual dangers- jailers, wallers especially in dungeons, and things like vortex/molten or jailer/plague on an already fast mob can be ugly- generally with space you can keep a good distance while kiting. In the open- as long as you keep moving it's usually easy enough to kite almost anything you come across. In dungeons/halls, it's far more tricky and I find SS becomes far, far more useful for evading swarms, whittling down tough enemies, or dealing with jailers/vortex/wallers or- my least favourite- the elite pack that just so happened to spawn twenty feet from the entrance so you have next to no room to kite without running into a fog of war zone.