I am not a massive fan of Trans Pennine Express either. The thing that annoys me most about them is that the first class section takes up far too much space, there is simply not enough seating room for standard class passengers. I have travelled during peak times (Mon - Fri) and weekends when half the carriage is a sparsley a filled first class and the other half all seats are taken everybody else is crammed in like sardines (and some people sat in the toilet just to get a seat!)
Now don't get me wrong, they are great locos for intermodal/inter-urban but they are certainly not suitable for long range, cross-boder services running WCML routes to the likes of Edinburugh and Glasgow. And to think that 5 years or so ago hst's were running their routes.
For me, an ideal situation would be loco hauled services similar to the Wrexham and Shropshire Railway Co. for long haul, cross border routes.