Hidden Complications with Tiscali

[#1]

I run a VPN to the US (Hector MN to be precise), no problems from my end. 19 hops and a couple of dropped packets at Level3, a few more at Sleepy Eye and an average end to end ping time of about 140ms. Nothing serious.
The problem appears to lay when the US end connects to us. Their tin-pot carrier (and the only one operating in the area) insists on routing the connection through Tiscali via their Chicago POP, fair enough, Plusnet has a direct port onto the Tiscali network and there are fewer hops, but "Oh dear!"
The moment it hits the Tiscali London gateway I get 150ms transatlantic hops, timeouts and dropped packets galore!
All the symptoms of an overloaded pipe and failing gateway and it seems Tiscali International's commercial support is rather worse than Tiscali consumer ADSL support.
Not strictly a Plusnet problem, just an unfortunate side effect, but really bad news when trying to run a VPN, big enough to force me to look for an alternative ISP, a shame after 10 years of happy Plusnetting

[#2]

Is changing ISP necessarily going to make any difference if the "tin-pot carrier" still routes through the Tiscali network to your new provider? 

[#3]

Changing ISP will make no difference as it is still likely to route through the same london Tiscali gateway as that will be the international connection between the two countries. The only difference will be it takes a slightly different router from that gateway to your new ISP but will not solve the gateway problem.
An ISP cannot control how data is routed outside their network!

[#4]

Actually the ISP does make a difference!
In my particular case, routing to BT is done via AT&T for instance (same as PN used to be). While Star Internet is routed via BT's own trans-atlantic pipe. Pipex/Bulldog/Demon also suffer from Tiscali International.
So if all else fails, consider it a warning. If you need it to work in both directions, check both directions?
I thoroughly agree it is NOT a Plusnet problem, they are a victim of the circumstance and I said so to start with.
In all honesty this is the first time in 10 years and a dozen accounts with PN that a problem has been a show stopper; Floods, fires, bandwidth congestion, mail/web/cgi server problems, sudden rule changes etc included.
All spoiled for a ha'penny of somebody else's tar.
And that is sad!