I bought a Billion 7800N a couple of years ago and it has proved very satisfactory on my 3.6 km, exchange only, line.
The problem before was that my line was capable of supporting a good sync (approaching 9Mb/s) during the day but it would invariably drop out when the noise margin drops by around 4 dB at night. The exchange DSLAM would set a noise margin of 3dB during the day and it would go negative and drop out at night. This would cause the PN profile system to drop my speed for 2 or 3 days.
By using the 7800N I am able to lock the NM to a daytime 6dB falling to 3dB at night. The Phyr facility seems to help a lot as well.
I can connect for weeks at a time at around 7.4 Mb/s sync.
The only possible fly in the ointment were the many internet reports from around the world concerning eventual wireless failure due to degrading of the hot melt glue used to secure the aerial connections and retaining clips on the mini-pci wireless card.
As the unit was almost out of warranty I decided to open the unit and remove the offending glue.
At this point I discovered that Billion had changed the formulation of the glue. I've never come across hot melt that didn't melt when prodded with a very hot soldering iron bit.
They seem to have changed to a loaded epoxy resin substance that didn't even mark after several seconds application of hot iron. I've left it all in place as I couldn't remove it if I tried.
Hopefully I can look forward to a few more years of reliable ADSL connection.
It would seem that Billion have listened to the earlier complaints.
