Inop, you're not the only one who feels like this...
Yes, people have problems greasing the -800. I find that it needs a slower thrust reduction than the -700, and that it is VERY speed-sensitive in the flare. Drop to Vref at the screen, and you'll also drop out of the sky. That said, this aircraft is so runway-hungry that adding a few knots to make the flare easier is not a justifiable option.
You probably know, and use, the 'slight pitch down for touchdown' technique - you know, that little forward movement of the control column to de-rotate the fuselage to a slightly more level pitch attitude just before the MLG touches, which sorts out the oleo alignment, causes the MLG to be travelling up with reference to the C of G, and so on. Well, the -800 seems to benefit from a slightly later and more aggressive pitch down than the shorter Boeings.
Hope this helps. If you're going to refine your landing techhnique, please do so carefully! Smooth landings are possible in the -800...
...but don't forget that a safe landing is on speed, in the right place, and slightly firm.