predator 4K2 with Z2 shaft

[cram]

I want to buy a new pool cue and I am considering the predator 4K2 with Z2 shaft.
Are there any real (not the design) differences between, let say a 1K and a 5K Predator cue?
Are there here people who have experienced this cue (i.e. shaft)?
Do you think that it is possible to find other cues (other brands), but cheaper, with the same global 'quality' (deflection, etc.)?
Do you know interesting (cheap, experienced, etc.) sellers in Europe?

[dutchboy]

I purchased a 4K a year ago, beautiful butt, inlays and all...but remember, you can put a great shaft on a broomstick and get good results...No need to spend all that bread...I've got a 20 year old viking with a stiff hitting shaft and I've put down the predator in favor of it. Wish I could get my money back.

[cram]

You're right but how can I be sure that the new shaft (z2) will be compatible with my actual stick? Do you know a site where I can find what cues are compatible with the Z2 shaft?
Marc