Sigma 70-200 HSM II vs. Sigma 70-200 OS

A little back story...I used to own the Sigma OS. It was my first 70-200 f2.8 lens, I loved it, but I lost my job so I had to sell it.

Now that I'm finally back to work I want to pick up another but I find myself wondering if I should save a little cash and get the HSM II instead (no matter which one I end up picking I will be buying used, so there is a $350-450 difference in price between the two). The problem is that while I've used the OS version I have never used the HSM II version.

In the research I've done I've read that that HSM II is prone to focus shift but less prone to focus breathing. Looking at DP's lens comparison charts it seems the HSM II is not as sharp as the OS at 200mm but is just as sharp or sharper in the lower focal ranges.

So honestly, to those who have used both the Sigma 70-200 HSM II and the Sigma 70-200 OS, is there a visible difference between the two when it comes to IQ (sharpness, color's, contrast, ect.) and how bad is the focus shift?

I have the Sigma 70-200 OS and always shoot with it handheld. I don't think there's any way I could go without the OS on this lens. Granted, the other model is probably a little lighter without the OS, but either way I believe I would have a hard time shooting at 200mm handheld without the OS.

Understandable, but the majority of the situations I shoot in don't require OS and like I said I've owned the OS so I know what it's capable of. However that's not what I'm asking I this thread.

Just looking for people who have used both to tell me, in real world situation (not pixel peeping) is there a noticable difference in IQ between the two and how bad is the focus shift on the HSM II?

I had the HSM II and was not all that impressed. At times It took decent pictures but nothing extraordinary. I would stick with the OS, from what I understand its much sharper wide open

Yeah. You want the OS version. The HSMII was decent and is decent for the money. But for the price difference you are getting both OS and sharper images - especially wide open where the HSMII was really pushing the borderline of usability.

OS!

I did love my OS and after I had to sell it swore I would own another......guess I never should have second guessed myself.

I am too old and shaky to use a 200mm lens without OS on an APS-c body.