70-200 f2.8L USM or 70-200 f2.8L IS USM II

[TriGGy]

The ISII is a great lens but it's really heavy. It would break you neck with a normal strap. You'd need a Black Rapid or something. It's great indoor. I had great success with it at a wedding. I've used the F4 70-200mm. It's really light in comparison. The F4 being the only issue with it. It's a very sharp Lens too.
http://www.flickr.com/photos/fergalocallaghan/8110366347/#in/photostream

That was an excellent shot there Hector.

How is the bokeh with the 70-200 F/4? Does it do an acceptable job isolating the subject from the background? I would most likely position the subject with a vast background behind him/her on F/4 with the help of compression. I tried it at 105mm with the 24-105mm but I am not satisfied with the bokeh.

[neuroanatomist]

Normally for adult head/shoulder shots how far can you get from the subject when using FF?

A good distance for an adult head/shoulders portrait with the 135L on FF is about 8-10 ft (2.4-3 m).  The reason 135mm is the 'classic' head/shoulders portrait lens is that distance is just right for a flattering perspective, for not being 'in the subject's face' and not too far away for communication without raised voices.  Perspective is important for portraits, and it's determined by distance only, not focal length. That ~8-10' distance is key, consider the other 'classic' portrait focal lengths - 85mm for torso, 50mm for full body, 35mm for environmental (full body plus location), all of them frame the subject at that same 8-10' distance.

[TriGGy]

A good distance for an adult head/shoulders portrait with the 135L on FF is about 8-10 ft (2.4-3 m).  The reason 135mm is the 'classic' head/shoulders portrait lens is that distance is just right for a flattering perspective, for not being 'in the subject's face' and not too far away for communication without raised voices.  Perspective is important for portraits, and it's determined by distance only, not focal length. That ~8-10' distance is key, consider the other 'classic' portrait focal lengths - 85mm for torso, 50mm for full body, 35mm for environmental (full body plus location), all of them frame the subject at that same 8-10' distance.

Sorry I wasn't clear about my question - I was asking about the 135mm, and you answered my question plus more - thanks! I was concerned that I may have to go farther than 12 ft with the 135mm when shooting adult head/shoulders pics that I have to shout. 

[dhofmann]

Could it possibly be that DxOMark is wrong???   

That's one possibility. Another is that the resolution may be better on the old lens even though the contrast and chromatic aberration are better on the new lens.

[Dylan777]

I use to have 5-6 lenses in my bag and now just 3 most use.

1. 24-70 II - it's on my camera most of time - indoor
2. 70-200 f2.8 IS II - when kids running around front yard & Portrait shots
3. 16-35 II - landscape

[TriGGy]

I use to have 5-6 lenses in my bag and now just 3 most use.

1. 24-70 II - it's on my camera most of time - indoor
2. 70-200 f2.8 IS II - when kids running around front yard & Portrait shots
3. 16-35 II - landscape

The best three lenses to have! You got it all.

[SDsc0rch]

I use to have 5-6 lenses in my bag and now just 3 most use.

1. 24-70 II - it's on my camera most of time - indoor
2. 70-200 f2.8 IS II - when kids running around front yard & Portrait shots
3. 16-35 II - landscape

THIS