When the 395's were in the design phase the consultancy I was working for at the time was involved, contracted to Hitachi to assist with UK infrastructure interface, and I heard a senior consultant recount that when they'd reviewed the proposed bogie design Hitachi had been told that, while it may be fine for HS1 operation, it would not last when operated on the SE "traditional" routes.
Hitachi reportedly expressed surprise, as they said it was their standard bogie design and it met all of the European standards, but were told in no uncertain terms that it was not robust enough and needed beefing up to cope with UK infrastructure.
In the last week I've heard a consultant who was involved in the CAF 195 design in a similar role recount exactly the same experience....