So I used Rabiot as a RCM in 4-1-2-1-2 (2) in weekend league and he was very solid for me. He feels much faster than his normal card and his shots are way better, His tackling is very strong he wins air battles most of the time because of his 6'4" height. He is pretty agile for that height and is good enough on the dribble. also his passing is very good. Only downsides to him are his workrates wich are High ATT and Medium DEF. I would like for him to have Med/Med or High/High. Another weakness is his weak foot, it's 3* and it sure feels like it too. He does get pretty tired after the 75th minute at least for me (I have him Stay back while attack and he still attacks so he is pretty much a box to box player for me). Overall The price of 280k isn't too bad considering you get some packs back (I got two walkouts, Fernandinho and IF Butelle). But I don't think there is that much of a difference between him and his base card, so if you have the money, I would go for it because the shooting upgrade is pretty good and overall some nice improvements. But if you are on a small budget just stick to his normal card it does the job.
Long and short passing
3* weak foot
High medium (too attacking for my liking)
Price compared to normal card