Which would you pick for a 10.5" pistol?

It's hard to beat the Magpul Pros for value.  They are fantastic; they lock sturdier than even my KAC micros

I think you're right.  Watched a video comparing them and they are almost the same size.  The MBUS are also steel instead of aluminum.  I don't think the overall weight is that drastically different either.

And the Magpuls are cheaper.

I did not like the spikes micros.  I bought a pair when they first came out. The removable aperture is easy to loose and the adjustments were too easy to move and not tactile, especially the front, so I felt it would be easy to inadvertently knock out of alignment.  I switched to mbus polymer sights for awhile then to mbus pros to lessen the footprint and improve sight picture, I'm happy with the mbus pro's.

What about the Griffin Armament rear? it looked like a decent  option that was available at Joe Bob outfitters for about $80. 

The Griffin Armament M2 sights look good too. I will have to check them out.

You should also check out the Magpul Pro LR rear BUIS.  It's adjustable for elevation and windage, is low profile and very solid.

I just picked up a set and they are very good IMHO.

MBUS Pro is heavier than MBUS. The Griffin Armament are the same as polymer MBUS. Spikes is lighter. We are talking a 1oz or less shift up or down from MBUS polymer set.

Griffin Armament attaches with a set screw driving into your rail instead of clamping from the side. Spikes has had cross bolt failures, the rear has the adjustmen on the wrong side, and other issues. If you don't have an ultralight build MBUS Pro are best. If you do, Spikes is lightest. There is only a bulk difference in the Griffin Armament and polymer MBUS. Not worth it to put a set screw mark on my rail.

Not only is the MBUS Pro steel, but it is nitride treated (think Melonite, Tennifer and such).  This is an extremely hard and corrosion-resistant surface hardening process.  Same as with nitride barrels and Glock slides.