Yes. I have it for this very reason and it's great.
My DS1 is 27 months and 98th centile for height and 16.2kg. My DS2 is 5 months. It has been brilliant.
When pregnant I really struggled to carry my DS1 and so used it as a single a lot. I replaced a Bug Cam 2 which was not as user friendly as the vista 2015. It is a great single. Big tall seat, huge basket and very sturdy for such a big lad. My ONLY slight quibble is that it is about 2-3cm wider than you would ideally want, but this is to accommodate the second seat of needed.
When DS2 was born I loved the carry cot and seat configuration, which really worked well and didn't religate my poor toddler to a rubbish seat. He could still chat and didn't feel put out by the baby coming along. The huge basket was a godsend with two.
I have since bought the buggy board and my DS1 is great on this. Now that he is a bit bigger. I have used the carry cot, seat and buggy board when looking after my niece, who is also just 2. The vista coped with three with ease.
I have a be safe Isi go car seat and it attaches well, making it a great travel system.
My DS2 is now 5 months and just come out of the carry cot (7.88kg and 50-75th centile). He to is long. Consequently we use the car seat/ seat configuration a lot, moving DS2 from seat to seat depending on whether DS1 happens to be walking.
I had thought that j would buy the second seat about now, but I've decided not to. Firstly my DS1 is getting very good on the buggy board, secondly I concerned that my DS1 is over the weight limit and it may make the thing too tricky to push. Thirdly the second seat is quite expensive. To be honest, with the money that id put away to by the second seat, I've been on gumtree and bought a outnabout nipper double v3, which I use for long days out when I think they both boys will nap and the walking will be arduous eg. A day at the Eden Project etc.
It does take up a lot of boot space, but interestingly for me is easier to get in my boot than the Cam. Must be the shape and the fold.
My only other quibble (apart from the width which is not really an issue at all) is that there really is not a 'nice' footmuff to go with it. Nothing that fits well unless you like the shell suit material shiny number offered by Uppababy
In summary, I have been hugely pleased with it. If my DS1 was just tall and not heavy, it would probably have been perfect. Not that there is a perfect pushchair!!!