lewong said:So f/3.5 ok for shooting inside the cathedral, meusum, or other indoor places of interest?
All I can say is that usually it is quite dim inside. If you want to shoot handheld, you'll have to increase your ISO, and find ways to support yourself. Also if the place allows, use your flash where neccessary. The best is to use a tripod, but there are some churches and museums that frown on the use of tripods, so you may want to consider a monopod. Also, there are also some places that don't allow photography inside their buildings.
I had used my Tamron 19-35mm f/3.5-4.5 around Europe, and I don't find it a problem.