I was lucky with mine - although there are the inevitable spots of rust, it had a full Ziebart treatment from new which has certainly helped delay the issues.
Mine didn't unfortunately didn't, and it got to the point where a full restoration was needed which I had neither the space, time, nor budget to do justice to it. Which was a shame, because for me at the time it was pretty much perfectly suited to my needs and I liked it enormously.
I've always like B GTs, and to this day the shape to my eyes is timeless. A properly restored and maintained example would make a cracking daily car, especially in Frontline LE60 form.
if I had to have only one old car and use it daily I'd go for a bgt for sure.
For me, that job goes to the Landy. Enormous fun to drive and capable of everything I could need - especially in this weather!