You probably have to know London a bit to fully enjoy the story of Neverwhere (the series or the novel for that matter). The whole story relies on knowing a bit of the city layout, above and below :) And it's understandable that US viewers can be surprised by the low budget BBC production (unless they were familiarized with it through stuff like Dr Who which seems to be popular at the moment). Most European TVs don't get to sell their productions abroad so they won't invest as heavily as the US productions.
I read the novel long before I could get my hands on the DVD (actually way before I was even aware of anything being available in filmed form, much less as a DVD). For some reason the only release seems to be for the US market.
Regarding the Neverwhere series, yes, while the cast is mostly good, some of the actors are so-so. Even with the obviously shoestring budget, the sets and costumes are quite inventive and convincingly used. The directing unfortunately is really poor and it does quite a bit of damage to the effectiveness of the whole.
If you have read and enjoyed the novel, you will find the series to be something imperfect yes but also something that you can watch with fondness. Possibly a proper adaptation by a proper director with a decent budget would be nice. But it's unlikely it will ever happen. Isn't it better to enjoy what's available even if it could theoretically be better ?
