I’d say… it depends.
If they can do it cheaper than Avanti, possibly. Presently, I use mostly off peak trains from Euston to Carlisle, and if theyre off peak, I’m not sure I’d like to see peak! However I only use the train because work are paying for it - the car is nearly always cheaper, and on a number of journeys, faster - especially if heading East-West.
It probably also depends on their stopping patterns - I’d rather not use one that crawls via Birmingham stopping at every lamp post if I can go direct. Again, price will have a bearing, although as my employer is paying, I can afford to be a little bit more lax.
Let’s watch and see what paths they get - if any.