Re: Everyone is Missing the Point!
That is exactly why I said (in an earlier point) - read the small print (yours too, not just theirs).
What is your replacement strategy? Do you do a rolling replacement (ala new age telcos like Level3, Sonus, etc)? Do you replace upon failure or based on demand only like most incumbent telecoms? Do you replace on a known cycle like mobile based on standard generation change?
If you rolling replace - H and Z are out of luck. Your timescales are not their timescales, their kit is out of the network before they can reap the fruit of the long wait. That is why rather unsurprisingly you will find very little H and Z kit in such networks. H and Z do not sell to them.
If you replace strictly upon failure and demand without scheduled replacement - you are royally screwed. H and Z kit will be in your network _AFTER_ the "cheap" contract expires and they will take you by the balls and your soul and mind will follow. If you have outsourced them the support (as someone mentioned Sunrise a few posts above) ... Well... you get whatever Christmas you deserve and H and Z are not at fault that your tech strategy is err... how to put it politely... idiotic in its commercial ineptitude will be a good description.
If you have a standards based generation change replacement cycle like mobile here are some news for you - H and Z are on all standards boards and they actively drive them in a direction which they like - some of that with some success. It is to some extent better than the failure driven replacement - you can try bargaining for your "best guess" support timeframes and sometimes get them.
In any case you really have to do the math on _THEIR_ scale - 10 years or longer. I you do not, well, there will be some bad news for you and read lots of fine print.