Fwiw I have been a user of VOIP for about three years and I summarise
my experiences so far as follows:
BT/BBV - I used this a lot first on a Cisco ATA 186 then on BT Voyager
10v. The call quality and connectivity has always been excellent but
dealing with BT is a pain. This was made worse when they 'upgraded' me
from an 055 No. to an 056 No. (which introduced limited connectivity
from a number of cable and mobile operators!) They seem expensive for
small business use (UK landlines) so reluctantly I wont be going this
way...
Sipgate - Their web interface, voice mail and free inbound No. were
great only the call quality I have had to UK landlines has been very
patchy/ropey sometimes unusable! (I was using the Cisco ATA 186 - I
suppose I will always wonder if a more modern ATA perhaps with a
different Codec would have been better - or was/is their network in UK
just cr**)
Skype - I have been very impressed with Skype-to-Skype quality and
reliability but far less so with Skypeout. Skypeout is just so patchy
for UK landlines. My experience would be 1 call in 3 perfect, 1 in 3
with drop outs and 1 in 3 total cr** thus I couldn't currently
recommend Skypeout for business use... (Their SMS and audio
conferencing stuff is nice though).
So I am now going to give Gradwell with the Camrivox Flexor 151 a
try...
Cheers,
Stefan