I thought this would come up, and is of course true. But I feel I've earned an upgrade as I have got fitter! More to don though obviously.The bike won't make that much difference, but your own fitness will ride hills more.
I'm not a bike at £500 will be much of a jump over the triban. I would rather spend the money on a better group set.
I read a lot about people uprating the triban and I did put new wheels on it but I would not go much further personally. The merlin malt r has tiagra gear on it which would be a step up for me.
I take the point that a jump from the tri 3 with new wheels to a new £500 bike might not be a big enough jump. But the merlins rrp is £750. Maybe that's meaningless. Still thinking about it. I'm not sure I could justify putting over a grand into a bike this year or next. Decisions decisions.