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.
2015 Stanton Ti Switchback
2006 Specialized Demo 8
2013 Specialized Allez Sport
1999 Santa Cruz Chameleon
1994 Cannnondale Beast of the East (rebuild still in progress)