I think they're good, but not amazing and they're IMO overrated. Hobb's a competent writer and the Farseer trilogy does have some good aspects to it - ie Fitz's characterisation, but there are some moments which just worsen the series for me. Her worldbuilding is terrible, but that isn't a huge issue. The characterisation is on the whole good, but sometimes a bit too simplistic, the same with her plot, but of course this is all focused on Fitz. So if you like Fitz, there's a high chance you'll like the series. But a lot of the other aspects are relatively weak - and the ending of the trilogy is one of the weakest I've seen, especially for a series that otherwise was pretty good. The story is a bit dragged out beyond its natural length, and I couldn't help feeling that the end of the second book was the natural end to the series, while the third felt as if it had been written just so it was a trilogy and kept the publishers happy.
See for yourself though, because a lot of people like this series, while others don't, and there aren't really any effective generalisations you can make. It's quite a dividing series in terms of opinion, much as Donaldson's Thomas Covenant (not that the two series are particularly similar at all - just in terms of controversy).