Tele-Arton 240 f5.5 for 4x5 verses 6x9

[mark e mark]

Hi, I plan to ger a tele-arton 240mm, or possibly 250mm, 270mm. I plan to use it for mainly 6x9 on a Linhof master Technical. I could also use it on 4x5. However, I have a oppertunity to buy a 240mm for 6x9. Is there much better resolution etc. With the 6x9 version over the 4x5? If not I might as well go for th r 4x5 version. But then is the 250mm much better than the old 240mm?

[EdSawyer]

I had the Tele Arton 270, but found the nikkor 270t to be a big improvement overall, in all regards. I actually have a spare 270t nikkor if it is of interest.