General is the lousiest tyre available on the market. I don't have experience of euro kontact (they're a new series), but radial st and XP 2000 are really horrible.
I've seen General tyres burst in every shape (around the bead, across the tread etc.), they have lousy road grip especially in the wet despite being M+S rated. They're very noisy and hard, so your shock absorbers get a good excercise and the ride is still hard. Moreover, they don't last long (around 40,000 km only).
I'd rather buy Maxxis MA-701 or Hankook Radial H706 155/70R12 for the money.
I'm sorry I'm very harsh but you see you didn't make a particularly good choice. One more thing is that just because radial ST and XP 2000 are bad doesn't directly imply that euro kontact are also bad. You can as well wear these out and write a good review for the benefit of others.