I've had both...
I loved my Shivers, they were truly great forks. I've never had any as plush since and I never really noticed the flex. I bought them from a guy on the bike shops race team who had hammered them for a couple of seasons, I then had them and took them to Morzine etc and they never missed a beat.
My 888's were on my Demo 9 and they were good forks too, but they weren't very progressive and made the most god almighty noise when they bottomed out. I never found the sweet spot with the compression settings, so just lived with the odd big bottom out, which was most noticeable on big slow speed drops. Can't say I found them noticeably stiffer than the Shivers. But they did look bad ass on an all black bike with the decals removed.
You won't go wrong with either fork.