I think the humour and characters of the games is what brought a lot of new fans during the last title...Awakening was a brilliant game (except the new style of the support system didn't 100% do it for me). It was so light-hearted yet heavy at the same time and the whole FE franchise is proof to me that intense gameplay isn't always needed to create a great story.
I was scared they were going to be similar just due to the nature that the paths of all the characters are bound to cross since they're, well, at war with each other. But it's good if they're not then...I'd be buying both anyway since I'm a sucker for the franchise... Will you be getting the Revelation DLC after Birthright?
And ikr, it's so difficult to find any FE fans online because it's just not a popular Nintendo outside of Japan compared to Zelda/Mario/Pokemon..although admittedly I do like it when less people know about these gems