They make for a formidable foe, but as characters themselves, I just don’t see it. They’re just big sky machines that destroy worlds. The Reapers are a good plot device, and clearly raise the stakes from Mass Effect 2 sufficiently enough that it feels like things are getting progressively tougher for Shepard to get by. I have no major qualms with my canon ending, trading my death for their destruction, although I did not enjoy the A, B, C binary choice presented to me - presented to everyone, despite how differently they may have played the game.
All that time, I’ve regarded the Reapers as solid but unspectacular villains. I have played the Mass Effect trilogy several times, although admittedly not for a few years now.