I agree that NSNA was initially overrated by Connery fans, but it's now overwhelmingly execrated today. But if MR is being reevaluated, NSNA might as well enjoy the same treatment.
Again, I think opinions are shaped by factors outside of the films themselves. I'd bet a lot of the disdain for NSNA today has to do with its "rogue" status: made by McClory in an effort to usurp -- or at least bloody -- the beloved Eon franchise, and forerunner of numerous attempts at a rival Bond series...surely a bad thing, right? Whereas in 1983 the same pedigree gave it the heroic appeal of pirate radio. It was David to Eon's Goliath; if the official series continued to deny us Connery, well then we'd just have to support an unofficial one, wouldn't we?
NSNA always struck me as uninspired (or in fairness, legally hamstrung), with a decidedly low-rent feel compared to the Eon series, with almost a "made for TV" quality to it, but on the whole it's no worse than the worst "official" entries. That said, I don't know that it will ever enjoy a "re-appraisal" since, more than any other Bond film, it's intrinsically tied to a specific moment in time. In 1983, it was an event; today, you'd have to explain to a new viewer why everyone was so excited (and it had nothing to do with the film itself). You kind of had to be there.
There are two excellent action sequences--the pre-credits skydiving and the laser battle in space (silly as it is)--and two macabre ones--death-by-dog and the centrifuge.
You know, the laser battle never really impressed me that much, and it's not because it's "silly." It's because Bond isn't in it. It's like someone sat around thinking "How do we re-do the underwater fight from TB and make it even less involving for the viewer?"
Barry's score is a little too slow and stately for me--its gravitas doesn't jell with the silliness that infects so much of the film.
I feel just the opposite: I think the "gravitas" added by Barry's score saves the whole enterprise from collapsing under its own outlandishness. The "Flight Into Space" track especially adds a grandeur that encourages the suspension of disbelief for long stretches of Derek Meddings' model work (which, while excellent even by modern standards, was not really what most viewers were expecting from a Bond film). When the space station is revealed in the sunlight, it's an awesome moment. We could probably make out the wires if we tried, but Barry made us WANT to believe it. Compare it to the scene in "Goldeneye" when the satellite dish (more fine Meddings work) rises up from the lake to a big, fat, "So what," thanks to Eric Serra's underwhelming score. The contrast between those two scenes demonstrates just how essential the right music can be to a scene.
Never once when watching MR in 1979 did I think the music was boring or sedate. That didn't come until I bought the soundtrack album later that year, and thought to myself, "Wait, are we sure this is from the movie I saw? I'm pretty sure that was an exciting film..." In the context of the movie, the score is perfect. On its own I'm alternately enraptured or put to sleep, depending on my mood. So anyway it's not one that gets a lot of play on car trips.