I wouldn't say they are more difficult to use, probably more 'fragile' and the reason for the price difference between the top end poles and cheaper poles is their performance at longer lengths, 16m+, so would say to get the benefit, you'd have to be using them competently at that length.
Mate, I have been the proud owner of an Air Z for 2 years now. It is one amazing piece of kit which is touch as hell and can be used for anything! Just get the "more power" package and you will be set for commercial purposes. If you want more kits - the preston DWA kits fit like a glove (and at £60 are half the price of a Daiwa top kit!).