I carry an L398A with me most of the time. It is a self-powered meter, so there's no way to increase sensitivity in dim light beyond the removal of the 'high' light slide. I've never had any problems getting usable readings in overcast, twilight or typical interior lighting conditions, but this meter cannot measure for long time exposures in near-darkness. Battery powered digital meters are best for that. The analog readings aren't accurate to fractions of an f-stop, but that's not usually a real world problem.
The 'A' is an updated model, and my understanding is that the photocell is improved over earlier versions. I like this meter because of the compact size, handy shape and the fact that it doesn't shut itself off after a few minutes and forget everything. The high light slide, manual calculator dial and extra photocell diffusors are a bit of a bother to fiddle with, but not a big problem.
The basic design of the 398 is unchanged from the original Norwood Director meter of 1948. It's a classic!