I am reading the first book, half-way through it currently.

While the first chapter was (imo) terribly uninviting and I almost gave up then, the rest up to now is ok.
Some things I don't like, but others I do. For example I don't like the funny elements, like
Spoiler Alert, click show to read: 
the 3body.com virtual game, and the rather ridiculous goings-on there, including Newton having a swordfight with Leibniz. Or the pacing, which is a bit off - the countdown starts at a strange time, and starts first on the photo negatives, then moving on to the actual retina of one of the protagonists.
, but other bits and pieces are cool, and the use of language isn't too grating.

I am rooting for the aliens, but
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unfortunately I already have read a synopsis of the later books
.

Style-wise, I think this author is competent enough. His use of language is perhaps a little better than (say) Philip K Dick's, although the actual ideas are not presented in a very refined way and come across a bit mechanistically in my view.