Although I agree I was missing the 'Star Wars' feel in certain aspects, I feel that we were very lucky to get Giacchino.
I'm not a score connoisseur, but I do love me movie soundtracks; of course Star Wars was what started it all, but then I was a kid of 8 years old when I saw the OT on VHS, so I just didn't think anything of the music.
However, when Lord of the Rings hit theatres, I noticed myself being intrigued and excited about the music in such a way that my friends just weren't. That's when I discovered that film scores were unique and different - and very pleasant to listen to - so since the early 2000's I really got into collecting and listening to them (although with Spotify now it's just as easy to find the scores there instead of buying them).
For the last few years there has been this 'Zimmer-craze' where Hans Zimmer (and people who were trained by him or sound a lot like him) has gotten to compose for almost every major blockbuster.
Now don't get me wrong; I love most of his stuff, but in recent years I really feel he's become somewhat repetitive and lazy and most of his soundtracks all have this same sort of 'electronic deep bass' sound that only evokes 'testosterone!'
Michael Giacchino so far is someones who I feel is closest to John Williams; uses the entire orchestra, not so much electronics and uses his score to evoke emotions whilst you watch a scene.
It seems the trend in Hollywood last years is to downplay the soundtrack and not let it stir you at all. Although this is commendable (giving the actors and actresses more freedom to convey emotion) it does have downsides - just look at the YouTube vid of E.T.'s ending without Williams' score; it's completely lifeless.
Luckily there are others besides Zimmer like James Newton Howard and James Horner (although he unfortunately passed away last year) that do stir the emotions and are great at sci-fi/fantasy scores, but so far Giacchino reminds me most of John Williams (just listen to Super 8 or John Carter or Jupiter Ascending).
That being said of us being lucky to have Giacchino and him being the closest to what one can get right now in the world of composers that sound like John Williams; I too felt there was missing something.
Of course the main scroll not being there was a big loss; not only musically to just hear that wonderful theme, but also as a Star Wars experience.
On the one hand I could understand the makers for leaving it out - as it a Star Wars story and not an official Episode 3.5 or something - but sitting in the cinema and reading those famous letters 'A long time ago, in a galaxy far, far away...' and then preparing yourself for that big booming blast of Star Wars across the screen, only for it to not come was kind of a big miss.
Besides that John Williams goes for character themes or just themes in general, whilst Giacchino mostly goes for one or two central themes and just 'wings it' according to the scene.
Of course Williams also looks at the scene and 'guides you through it', but he still finds ways of highlighting certain characters (Rey, Han, Finn, Kylo) or certain feelings/emotions (hope, love, anger, etc.) and I did miss that in this score.
There were definitely some highlights, but none that jumped out as for instance Williams did for TFA; 'Rey's Theme' alone and the ending with 'The Jedi Steps' are phenomenal, as well as 'The March of the Restistance' and 'Kylo Ren Arrives at the Battle'.
So yeah, hopefully Giacchino will keep improving on his work and the basis he laid here, because I think - and yes, I know that's an awful thing to say, but let's be realistic - that once Williams is gone, Giacchino will be the best replacement we can hope for, as he's capable of amazing things.