My favourite European city - I worked there for a time and go at least twice a year. As others have said, it's changed over the last few years and has become far more glossy-touristy with consequent price rises, though it's still reasonably priced by GB standards and if you get out of the centre can be very cheap. I can't, I'm afraid, agree about the "tipping culture"; the Czech tradition has always been simply to round up to the nearest convenient figure and big tips are not expected. If you find hotel/restaurant staff expecting big tips you're being ripped off. I'd avoid the taxis - apart from taking your life in your hands you'll be overcharged like there's no tomorrow. Public transport is easy, cheap, reliable and safe - use it and you can get almost anywhere quickly. It gets uncomfortably hot and humid in the summer, so I'd recommend going between September and May if you can; June can be quite nice, but only if there happens to be a fairly constant breeze. I try not to go in July or August unless it's absolutely necessary; apart from the heat & humidity the place is crowded, the prices jacked up and most of the theatres are closed.