Aircraft recognition does have relevance on a pilot forum. The safety issue of being given a conditional ATC clearance based on type recognition was discussed in CHIRPS about a year ago.
If you are told "Line up and wait behind landing A330" you need to know what they look like. The airport I did most of my VFR training at had a huge traffic pattern and I was regularly told eg "follow the Pilatus on base". Solution was to buy Janes Aircraft Recognition Guide.
Incidentally, Dartagnan;
The A320-100 has no winglets
It is possible to fit winglets to 737 classics (our company considered it)
Some 737 NGs do not have winglets
Not all 737s have the small windows (ours are being removed!)
