I have the same PLUS an ip6, a 13" MBAir, a 15" rMBP, iPad Air, iPad 4, iPad rMini, and multiple desktop variants - basically everything Apple makes lol - and I STILL got the iPad Pro and I LOVE IT.
Having the extra real estate for everything I do is really a nice add, same with the extra processing power and increased RAM. I don't use it for games or photography or even work; I use it for research, reading academic journals, taking research notes, performing data analysis, etc. It is extremely useful for me having the ability to read digital docs (word, PDF, PP, etc.) in full size, editing and marking up digital docs, and being able to read/write notes while viewing a research document or website page for reference simultaneously.
The only thing I do not like is that web pages load in a mobile theme instead of a desktop version because of iOS. That being said, all you need to do is switch to a desktop page when needed. Not a big deal really when compared to all the other benefits in provides me in my particular use case needs.
Your own PMMV depending on use.
Hope this helps.
Best,
JS