I have to say, having experienced both the seniority based system in Australia and the allocated system up in London. I prefer the allocated system - at least everyone gets a reasonably fair share of trips.
Yes in the greater scheme of things, I'm junior back in Australia so I don't get a lot of choice, but that's not why I'm suggesting that the system needs to be reviewed.
I think there needs to be a little more equity, not just in the trips but also work positions.
Indeed, maybe the current system is worthwhile keeping, but I think some alternatives need to be investigated and put to all.
However, I don't think anything is going to change in the near future and whilst I understand that there is still a view that you should "do your time" the concept of that type of seniority is well and truly buried in most other industries. Seniority based selection has been replaced by merit or equity based selection. The sooner we move on with the rest of the industrialised world the sooner we look less like dinosaurs.
Anyway, I'm sure I'll get a canning for this, but hey.... I'm getting used to it