I have both the 20 and 25, and the 25 is a better lens in all respects except size and price. Yes the 20mm is kinda loud compared to the 25, and the 25 focuses faster. I got a great deal on my 20mm as a kit with the GF1, but if I were choosing between the two I'd probably just go for the 25mm. That being said, the 20mm is an optically excellent lens; it's basically the reason I chose the GF1 kit over the EP1 kit, and largely why I chose m43 over NEX. I still have far more pictures taken with it than any other lens on the GF1. The two are quite different in field of view also, so I don't really consider them as filling the same niche. I'd probably even use the 20mm more often than I do if I didn't also have an X100 (which has identical vertical FOV and only very slightly wider horizontal FOV than the 20mm on the GF1). I would also suggest the Panny 14 2.5, but it's kinda wide for what you describe, and I find f/2.5 a bit too slow to freeze subject movement without using flash. In reality though, all of the m4/3 primes that I have (14 Panny, 20 Panny, 25 PL, 45 Oly) are so good that you couldn't go wrong with any of them.