The problem is, they were at best average for their time, but this is almost always true, as the perfomance is defined by the legal requirements at the time, the technology of the time, and in cost constraints terms, by what ever the manufacturer had to do to seem to keeping up with the Joneses: basically three pretty compelling reasons all headlamps of any era will be average for that era.
Now years and a generation or two later in car terms, and they are shocking in comparison (you could probabably compare some other car technologies and come to the same or even more vehement conclusion, eg sat navs)
So having upgraded both my 993 and 996 from their relative candles (compared to my brand-spanking daily driver xenons at the time), I can say the process was worth it.
For the 996.1 originally without projector headlamps, I just used the plug-and-play Litronics (mono-xenons) and for the 993, which was supplied with projector headlamps, I just upgraded the internals as per factory (but using modern components - ie HIDs)
As for MOT, neither washers or levellers are required.
The washers are like rear wipers: if they are there they have to work, otherwise it doesn't matter, and the levellers are exempted on hard sprung sports cars like 911s, and explicitly for vehicles with no, little or 'negative pitch' luggage capabilities.
Having said that, non-OEM standard HIDs pose issues in non-projector assemblies (not an issue for 996.2 onwards), as the off-axis/unfocused beam produced by inappropriate HIDs in incandescent parabolic assemblies can fail an MOT due to the uncontroled light beams.
Additionally, extreme non-OEM spectrums and output power can fall foul of the same output control requirements.