In a store I now tried the Prophet 6 and Oberheim 6 side by side.
I compared both of them by trying on them to get the same sound and how they differ, how close it can get, by
the brass sound and all onboard effects switched off.
With basic tones, sounding the same, but they seem to be somewhat different beasts since their programming is different. Now THAT was their only and biggest difference to me besides the price tag.
They both -- Prophet 6 and OB-6 sound crisp when just trying out the basic tones and if being skilled programmer on both then they both can sound the same.
Then I tried to program a brass sound on both which would sound the same on both.
About that Prophet 6 at the first moment it felt to me that I am ready to buy with eyes, but the messy programming experience on that Prophet 6 model made me to think again, becouse while it was quite effortless to get the same sound on my vintage Prophet P600 at home, and I got very close result on a OB-6 too, which was also okay, with that Prophet 6 I messed atleast 15 minutes around and did not got that closest result just becouse of its programming interface.
In my opinion in this case the closest match to old Prophet P600 would be the new OB-6, but only becouse to me it was simpler to program to get that particular desired sound what I have done on every synth I get hands on.
So, now I am satisfied, and... I will go back to my Roland MKS-80 and Prophet P600.