Hi! I have a GX1 with a 20 mm and 14-45 as my lenses. Use - travel/street. I plan on keeping the GX1 for awhile as I like the size/build/discrete etc. But I'd like a little more reach - 35-100 f4.0-5.6, or maybe just the 45 1.7 prime? The latter doesn't increase the reach, but I'd have a 20/45 prime travel kit. So it comes down to a choice between the two. Is there a big difference in IQ between the two?