I am commenting on this miniseries from the perspective of someone who read the novel first. And from that perspective I can honestly say that while enjoyable, I can see why it hasn't been rebroadcast anytime recently. More specifically, this mini has some serious problems, such as:
1) It is terribly miscast. The actors who played the younger generation were all 15 to 20 years older than the characters. Ali McGraw (45 at the time) was playing Natalie Jastrow who was supposed to be about 26. Jan-Michael Vincent (39 at the time) was playing Byron Henry who was supposed to be about 22. The other Henry children, and Pamela Tudsbury, were also played by actors way too old for characters who were supposed to be in their 20's.
2) Some of the acting was absolutely awful. Ali McGraw at times almost made this mini unwatchable. I have seen more convincing performances in high school plays.
3) The directing was poor. To be fair to Ali McGraw, the bad acting and character development were probably the directing. The portrayal of Hitler was way overdone. His character came off looking and behaving more like a cartoon villain than the charismatic, sometimes charming, but always diabolical genius Herman Wouk painted him as in the novel. Some of the other characters are done so stereotypically (Berel Jastrow) they do not gain the depth of character that Wouk created for them.
4) This mini is very dated. The hokey music, the pretentious narration (it sounded like a junior high school history film narration), and the entire prime-time soap opera feel of the mini made it almost comical at times. Also, too often Byron and Natalie are costumed and made up to look like they are in 1979 rather than 1939.
Someone who watches this without the benefit of reading the novel first will probably not sit through it all, because it will come off more as a late 70's / early 80's "take myself too seriously" prime-time soap drama, rather than the television version of what is certainly a modern American classic.
Remakes of older movies and the like are sometimes poorly done, but this is probably one case where a creative and inspired director could make a very stunning, memorable, and critically acclaimed production. I don't ever see that happening since a remake would have to be just as long (15 hours) or longer to do it right, and given the short attention span of most of the current American viewing public, it wouldn't fly.