I think its worth buying good quality cabs which sound great over a better quality amp and average cabs.
If you have an amazing head but some really cheaply made and nasty cabs, then then you are not getting the full potential out of your amplifier. Cheaply made cabs have speakers in them which offer a lumpy frequency response which will affect your overall sound. The actual cabinet enclosure itself too will also affect you sound, this includes to wood its made out off, the size of the ports and the amount of and quality sound proofing packed into all the dead spots of the box.
Once again as stated previously, only one person can decide upon which brand to go for and that is yourself.