Why, please, does BT consistently report Ping on my (fibre) line far higher than either TBB or Ookla? Like just now - 33.13 against 16 and 17 respectively?
Probably down to the way they are measuring the latency, none of those three results are true ICMP ping anyway, they will all be measurements of small packet latency which usually is very close to ICMP ping.
Generally yes. If wanting to check pings then the command line ping and tracert (traceroute) commands are best or our tool like http://www.thinkbroadband.com/ping for long term tracking