In terms of quality, obviously you'd expect the cheaper lanterns to be worse. A failing GRP is more of a design fault (Philips later coated some of the GRP canopies like the Iridium). It's difficult to refer to quality without design faults, however the Streetfighter I see as a cheap and nasty lantern, which goes scabby really quickly and just doesn't look good. The 2600 is also another basic lantern which was really overrated in the past, bearing in mind there were other better made alternatives on the market.
I'm going to get shot down for insulting this lantern now (
) but I don't think Lucidors are great in quality either.
One think that genuinely surprises me is the plastic canopies that were used on a couple of lanterns in the 50s - Where the canopy lights up slightly (but not enough to cause sky glow.) Canopies on the Metrovick SO-50 and the Beta 3 stay clean and fresh, and despite being installed in the 50s, the canopies could pass for something that was installed in the 90s.