The Original Osram HQI-TS 70W and 150W had the following chemistry:
/WDL: Sn-Tl-Na.
/NDL: Sn-In-Tl-Na.
/D: Dy-Tl-Cs.
/CD: Don't know.

On the Excellence series, the chemistry is the following:
/WDL: Dy-Tl-Na.
/NDL: Dy-Ho-Tm-Tl-Na.
/D: Dy-In-Tl-Na.
/CD: Same as /D.

Why Osram did these changed? when moved from the old HQI-TS to the HQI-TS Excellence? Tin have a molecular continuous spectrum and less corrosive to the quartz than rare-earths, and Dy-Tl-Cs have higher CRI than Dy-In-Tl-Na.

Actually, I believe Osram moved all their original HQI-TS from tin to rare earth chemistry already sometimes in 2000's.

Why don't you take time to read James writings on these lamps? In short, tin radiates a lot into infrared, that power is completely wasted, so lumens/W are unimpressive. Also, while the color of tin lamp may be quite nice, measured CRI is stuck somewhere around 75. Rare earth mixes do not radiate that much at IR, and also, already give CRI of slightly above 80 in quartz lamps.

Excellence series lamps certainly get heavily optimized for costs, and probably life/efficiency again, so CRI actually regressed back to ~77 compared to earlier rare earth HQI-TS.



 

And why the /D has been replaced from Dy-Tl-Cs to Dy-In-Tl-Na? This decrease the CRI. And green color from Dy-Tl-Cs is mainly happening in the 400W and over, either as a result of old lamps or using a ballast with low ballast factor that underdrives the lamp.
Also: If tin halide produces molecular radiation in the visible, what are all the IR emission of it?

Who said earlier /D Osrams in 70/150W were Dy + Tl? Do you have any lamp or spectra to confirm?

The only low power lamp with this chemistry I have on hand is 150W Iwasaki FSW. And being Iwasaki, still I don't like it's color. To my eyes at least, Dy+Tl lamps almost always have that hateful green tint with high metamerism because of very narrowband green Thallium peak. I think I have only a couple of examples of lamps using that chemistry, which have acceptable color, orignial 400W /D Osrams and one no-name Chinese 250W in FC2 bulb. All others, including no-name 400W one, 250W BLV, 250W GE all are ugly green. Adding some sodium immediately tames this, turning that ugly cold greenish light to much more acceptable slightly yellowish light of ~5000K. 

And yes this *does not depend much* on driving power level. I especially experimented with a couple of lamps, new ones, driving them up +10 +20% *did not cure at all* that hateful green!

@RRK: Here is the light of my Sylvania HSI-TD 70W/D that I had before its ceramic lampholder broke apart. It had Dy-Tl-Cs, and had an impressive pure 5600K color without any green tinge to it.

But:

How do you got the idea this is Dy + Tl lamp? Spectrum? Datasheet?

Also this is not an Osram lamp. It may (or may not) have an Osram equivalent. I have for example a Sylvania lamp (double-end 150W MH) which has that Venture-style elliptic burner and NaSc fill, nothing like this was ever made by Osram AFAIK. Belgian made, but probably American Sylvania development?