  Sometimes I utterly fail to understand the popularity of a particular book. I can more or less figure out why people enjoy something like the DragonLance novels, or the Gor books, but I must say I am perplexed at the number of SF fans who swear by Larry Niven's Ringworld books. The first volume, Ringworld, was enjoyable enough, even if Niven failed to create a really coherent plot, or even to fully exploit the sheer visual wonder and sense of place that a contruct like the Ringworld is capable of evoking (take a loof at Arthur C Clarke's Rendezvous With Rama and compare to see what I mean). The whole sub-plot with Teela Brown and the Puppeteers' program of breeding humanity for the 'luck gene' is a perfect example of what was wrong with the book - more or less arbitrary tangents that seem to serve very little purpose, except to serve as more or less obvious plot devices. Still, the book was fuelled by a very cool hard SF concept, and had a certain racy wit to it. Some say the aliens were well depicted, and I will concede that they were at least more grown-up than the human characters. My verdict? A mildy entertaining SF adventure, but not even as entertaining as, say, Grant Callin's A Lion on Tharthee or Jeffrey Carver's Panglor, to name two hard SF novels that no one has ever called 'a classic of SF'.
Now we come to the sequel. It seems to have been written purely as a response to the numerous readers who took great delight in picking at the structural gaps in the Ringworld. Perhaps they should have spent more time remarking at the structural gaps in the novel. Everything about this novel smacks of sophomore slump, series-wise.
The plot is even more meandering and contingent, with the characters engaging in dull technical discussions and coming to rather unwarranted conclusions. I am no engineer or physicist, but I am at least clever enough to follow a logical argument, and I have to say that most of the big conclusions Louis Wu and Chmeee arrive at seem utterly unjustified by the discussions that preceded them.
The most annoying aspect of the book is the contant insertion of rishatra - a custom wherein members of species that cannot breed with each other engage in sex to seal agreements or release tension. Something just occured to me. Rishatra is the key to what this novel really is. Ringworld Engineers was written by Niven to shut up those MIT students who marched the halls of SF conventions chanting 'the ringworld is unstable', by deluging them with enough garbled techspeak to keep them crunching numbers for another decade, and enough (non-explicit) sex to ensure that they would be too distracted to ever do so. Yes, Niven's sequel was a fitting reply to the only critics who bothered about the original enough to respond.
But for those of us who are not virginal MIT students - nah, skip it. Personally, I gave up on the book some 50 pages before the end and have no intention of following up on the series (which has just recieved its 4th installment, Ringworld's Children). So have I really understood why so many people loved this book? Not really, I've just facetiously dismissed them with a string of stereotypes. But they're my stereotypes and I stand by them! 
