Siege is nothing ground breaking, its a relatively simple story which i dont want to spoil or cover here because thats why you should read it. Its solid writing, with great art and unlike most events is only 4 issues long. Its also a great jumping on point if you cant be bothered to go and find all the dark reign stuff that came before because it ties things up nicely to move into the heroic age. So from that perspective i can defintiely recommend it.
I wanted to comment more on the core story and all the ties ins. with any event i want to read the important issues, those that count. Unfortunately most events have a lot of pointless tie ins, and i have now read all related hardcovers and can confirm that aside from the core hardcover, you want to pick up the Thor hardcover and the dark avengers only. Siege embedded was filler and didnt add anything for me, new avengers was just tagged on because they had to but also brings nothing new to the story, and battlefield has one or 2 interesting stories but by and large if you want the core experience i can only recommend the 3 above.
All in all a good story but only 2 other hardcovers are needed for the full reading experience.