The Omega isn`t tyre sensitive really, you just need good tyres,leave the budget ones alone if you`re going to be driving "enthusiastically".
I think it is tyre sensitive. Very much so. Both from a grip viewpoint and a tramline/stability point of view.
Different drivers have different perspectives of what good grip is, and have different sensitivities to straight line stability. Mr Gixer, for example, is incredibly sensitive to any variances in straight line stability - I suspect mostly due to his bike track days - which is always the subject of heated debate during curry evenings.
I found the three tyre brands I used all fairly similar for stability and tramlining was minimal, but thats just judgement on what I have used. I would think that worn or poor suspension components would cause more issues with insability and tramlining than any tyre sensitivity, and that is the Omega`s Achilles heel, not to mention worn diff mounts which will be al of them by now.
At the time, you can bet your 'arris that Gixer's black saloon and my Silver Bullet were both as tight as a nun's do-dah...
...though now my diff mounts are tired (barely noticeable when driving - rear steering is normally another issue, usually doughnuts if geo is bang on), and my front verticals have just started to separate one side.
But as said, tramlining/stability is always a bit subjective, and in order, the TTs were better than the RTs in this regard, with F1's coming last out of the trio by some margin. None as bad as SC5s though. I don't think I'm overly sensitive to it, in the way chrisgixer is.