I don't know if this is helpful but we (I!) decided to get the deluxe carrycot to go with our city mini GT, for our baby due in November, let me share some of the stuff that went through my mind when choosing...
Originally I wanted the Versa for parent facing, but when we tried it out I found the fold clunky and so we decided on the city mini instead. Getting a carrycot meant that baby could be parent facing for a while at the start, and obviously the bigger the carrycot the longer that period might be. I think the deluxe is only a few cm longer and wider, but it is the extra depth that really makes it seem bigger. Some people say their babies have "grown out" of a carry cot at only 8 or 9 weeks, but that just can't be right in terms of length of the baby. However I can see that baby might not seem so safe in it once they start moving around more in it, and the shallower the carrycot, the sooner that might start being a concern. Personally I'll be keeping DD in it until she can sit up / pull herself up on the cot sides, or is getting bored of staring at the sky. I think the latter will happen first, but I'm hoping not for a while, as she always falls asleep instantly when I start pushing the pram so mainly watches the inside of her eyelids! She's currently 12 weeks, 12-13lb, and very happy in there.
Another plus with the deluxe is that we have used the carrycot as a moses basket when staying away from home for a night or two. I know officially they don't say it can be used for overnight sleeping (although as I understand it there are no tests for this in the UK, unlike the USA), but as it has a vented base and a normal moses basket size mattress, we are completely happy with using it this way occasionally. It saves room in the car!
Honestly though the main reason we got it was that I thought it looked way nicer than the other baby jogger carrycots, and we could afford it, and having waited for this baby for a few years, we thought, well why compromise. I don't imagine anyone would be disappointed having got the deluxe one, but on the other hand I can see that some people would be equally as happy with the compact one. It's a tough call...