Which 2700HGV to buy for hack/upgrade

[mortod]

Thinking of buying a business hub to replace my HH2 (I find the hubphone echo too annoying). But I'm not at all clear how to tell which one to buy:

• Is there an easy way to tell which ones are suitable amongst the many for sale on ebay?
• The very long and old thread here suggests only a single SSID and pre v6 firmware will work - is that still the case today?
• Are there certain serial numbers to look for?

One thing that puzzles me - if the v6 firmware is such a problem, then why isn't there a JTAG solution to flash it back to an older firmware (as for the HH2)?

[patioheater]

Not too sure that any of them will work with VOIP unless you have a bt business account