Overall, Awakening is a much less dignified experience, whatever that's worth to you.
Which is a way of saying that the quality of the writing for the series has degraded over the years. The new games lack any real gravitas, and are full of (stale) anime / manga tropes and clichés that, IMO, make them feel like a different series (if not for the game play). There are fun characters in there, but it does not feel the same, at least for Awakening and the Fates "trilogy".
Echoes is a distinct exception, IMO. The game play is old school, but so is the writing, and you can very clearly tell which parts of the story are from the original versus which parts are exclusive to the remake (e.g. the Supports, which often feel out of place to me). Fantastic character design, top-tier voice acting, just a fun experience for me. ... Do not play it on Classic Mode unless you want to be frustrated. Permadeath + really cheap AI and map design = not fun.
I got my start in the series on the GBA, and those are my favorite games (barring Echoes). I am one of the rare fans who really does not care for Path of Radiance and Radiant Dawn.
You said it better than I could have. Def surprised, given your opinion about Awakening and Fates, that you don't care for the Radiant games.
I will add to my previous post that Awakening was a lot of fun (in case anybody thought I was being too harsh on it). It just doesn't have the gravitas of most American releases before it, which are just as fun anyway -- and that's why I really jump off its train and jumped away from the series as a whole. ---