Is it the curvy shape? I hope not from my experience!
Back in '97 I had the displeasure of having to drive a 1.4 Astra estate for work, with a twisted driving position that used to kill my back (one of the reasons I left the job was they wouldn't let me use my Xantia instead).
It used to try and stall at 70mph on the motorway, yet Vauxhall couldn't find any faults logged despite the ECU warning light come on.
One of the many times it was in the garage they gave me a 1.6 Auto, unless I was going down hill or passed by a lorry I could not do 70mph as it would get to about 65, change gears, struggle and slow down, change down, get to about 65 and repeat.
Of course chances are the Vauxhall garage were just as useless at servicing it than they were at servicing my company car, which would explain why it was so bad.
TBH the "sporty" Vectra I was given while my Xantia had some bodywork repaired was horrible too, and NTL's diesel Astra's were ok, the seating position was slightly improved, but the only really good Vauxhall I've driven was my first car, a Mk2 Cavalier 1.3 (which everyone thought was a 1.6 as it used to shift).
Mustn't let Danielle see me posting this, her mum worked for Vauxhall and they're lethally loyal
Hope yours is a good one!
Re the 205, you cannot let one of the last decent Peugeots go!