Looking for a single point sling for a possible at pistol build....how do the magpul offerings compare with those from blue force gear and other companies?  Any other companies that make a good single point?

BFG has a huge following here, especially with the padded versions.  I have multiple slings, and I use them all differently.  I don't think you will go wrong with either.  You might want to get one that can go from a single to a dual just in case you don't like the single point.

It pretty much comes down to preference. But the BFG VCAS, Viking VTAC, and Magpul slings are all very popular.

We use BFG at work and have for years. Great product.  I just picked up a padded BFG VACS sling for my personal rifle.  Good quality

I run BF vickers 221 sling. I run my two point at the end of the receiver so its an easy swap to a one point or vice versa if needed.

I'm not a sling guru but I won't be using any other slings its easily adjustable easily converted for multiple sling options and its very comfortable.

I've been a long time fan of the Ares Armor Huskey Amentum Slider Sling.  I own several of the padded versions and I continue to purchase these primarily when I need a new sling.  The slider mechanism works a bit smoother than the BFGs I own.  

The most recent BFGs I've purchased have been the limited edition AK slings.  I still run a regular BFG on my AR57 and a padded BFG on my A4 clone as well.  They work as advertised and fill a niche for me.  

I've also been happy with the newer MS4 slings from Magpul, both before they moved to the newest slider and were still including the webbed loop to pull and after they moved to the newest slider that flares on the edges so the pull isn't needed.  My biggest complaint is that they aren't padded.  I know Magpul offers a padded sling option now, but I prefer a different type of padding in my sling than they offer.  This drives me back to the MS4.  

All of the slings I've mentioned are 2-point slider slings that can be easily converted to single point slings and back using the appropriate hardware.  Quality QD sling swivels and an IWC tri-glide with a QD socket will do the trick well.  That's how I set mine up.  I will say that the MS4 is the one sling in the group that stands out from the rest as providing the most natural single point sling feel while still offering the benefits of a 2-point slider sling if the situation warrants.  If I were in your shoes, the MS4 would be the sling I would choose given your application.

I'm a fan of Magpul MS1 slings. I use them on all my rifles. Some mash hooks, some straight to sling loop/stock, some QD's. VERY modular. I will say though, that they don't work well with mash hooks (as most don't) as mash hooks typically have a sharp squared off edge that does not lend well to sliding webbing.

Not much not to like about that sling.