With my eldest, he was in his moses basket for about 3 months until he outgrew it and then we moved him into his cotbed. We went for a cotbed for several reasons tbh, first of all I always knew I wanted another baby afterwards and that they would have to share a room which involved bunk beds because of lack of space. It seemed a waste to buy a moses basket, then a cot and then move onto a bed, when he would only get a couple of years out of it and be moved into a bunk. Secondly, as we wanted it to last him 5/6 years, the cotbed was a more logical option being bigger and the fact we could take the sides off to convert it. Thirdly, when it came to actually buying the cotbed, it was reduced in the sale and worked out about the same price as a cot so seemed better value!!
However, with our second baby, she is still in her moses basket at the moment but will soon be moving to a cot. This time we have gone for a smaller cot, one because of the space issue with there already being a cotbed in the same room, and two because when she is big enough we will be getting the bunk beds so rather than having to make 2 or 3 tricky transitions between beds she will go straight from cot to bunk and no bed in between!
Personally I would say it totally depends on your circumstances which bed you would go for, take into consideration the cost, the space and how long you want it to last. If we had the space I would definitely have another cotbed over a cot. I can appreciate the point of going straight into a single bed etc, but for me the transition from cot to bed is quite a major move for a child and if you can do it with the minimum of fuss then all the better. When we took the sides off my sons cotbed, we involved him in it so he clearly knew it was the same bed and didnt get distressed when he first had to sleep in it. Plus theres always the option of putting the sides back on if things dont go well!
If we had the space and the kids had their own rooms then they would both be in cotbeds until about 6 years old, by which time they would have their own opinions on decor and stuff, so could help revamping their rooms when it came time to get a single bed and the room could be completely redecorated to their own taste
As it is though, we are very limited which is why we have gone down the above route