To be fair to Bilstein, it was about 15 years ago
Around the same era I'd suggest

. In fact, the B4's that went on the back of the mighty Silver Bullet around that time - and everyone who had a go in that car said it was one of the best handling Omega's they'd ever driven - stayed on for over 100k before the car was scrapped in 2017, at whilst point the shocks and springs were swapped over to TBE and used as a daily to Coventry and back until the chinky batflu came, so probably did another 50k on that car as well. And, no, they weren't knackered even after that time.
I only recommend stuff that I have positive experience of, agree or disagree at leisure 
Exactly! Hence why I said that I felt B4's were every bit as good as OE/Sachs/ZF on performance grounds, but lasted significantly longer than the 30-40k I got from those.
It's also why I've always said those front suspension kits ATP used to sell are a waste of money, because, well, they are - they don't last and can't be refurbed. And why I said ATP as a company are a shit to deal with when things go wrong with the order or the item.