Looking to the hive for a reasonably priced AR (flat top) upper receiver vice block.  I have seen various units through my web searches, but would like to get recommendations from those in the know here.

Thanks in advance for your responses.

I bought this set along with the lower blocks as well because I needed blocks for a .308/ AR10.  If you only need one for a AR15 or just the upper blocks, they have a set for $17.  They work great and I have not had any issues using them.  Their magnetic vise jaws with a center groove work surprisingly well at holding a barrel to install or remove a muzzle device.  

PlastiXrevolution Upper Assembly Block

I use two different upper holding devices:

080-000-659WB Action Block & Lower Vise Block Set

... and...

080-000-637WB AR-15/M16 Barrel Extension Torque Tool

In my experience, the generic Amazon one will work just fine if you are using one with mil spec size and shape.

You really only need to get into the expensive one off stuff if using different shapes. Off the top of my head VLTOR is one example.

I use the Wheeler Vice block. It comes with a piece that helps you line up the gas tube. about $20 from Midway. I've used it quite a bit and never had an issue. It only works with milspec forged uppers, either flat top or carry handle versions. 

If you want the type that secures using the barrel extension, Geissele makes two versions. One is $99 the other $175.  The more expensive one allows for more torque to be applied. I think Brownells has their own version of this for less $$.

Magpul also makes one that secures via the barrel extension. Called a Bev Block, it's about $50 from Magpul and others.

The Wheeler setup makes timing barrel nuts easier.
However for the most part if it fits your upper and has an insert it should work.
I would not buy on price from some unknown.

Hey guys, thanks for the recommendations!  I will be checking out each one before determining which is best for my needs and budget.  Take care