I used to build stuff on the server, then i switched to extjs, with the server only exposing a bunch of json-rpc web services. It's not as big a deal as people paint it out to be. Extjs abstracts away browser differences well enough that i rarely come across issues that aren't reproduceable for me. If they're reproduceable for me in my browser, they're easy to fix.
Now, extjs is a DSL, it's closer to flex development than to traditional web development. It has a learning curve with a pay-off at the end, and the pay-off is easier ui development. If you're building ui the traditional way, but client-side, ymmv. Still, anything to do with rendering glitches is something you'll have to debug by eyeballing it, regardless of where you render your ui. There's no way of automatically logging misplaced floats.
P.S. There's also less to monitor. Typically you'll monitor for performance and security. Performance depends on the browser and pc specs, not the server's load, and security has nothing to do with the client. So, really, there's just not much to monitor. You can attach error handlers to automatically report exceptions to the server, but i've not had a need.
Now, extjs is a DSL, it's closer to flex development than to traditional web development. It has a learning curve with a pay-off at the end, and the pay-off is easier ui development. If you're building ui the traditional way, but client-side, ymmv. Still, anything to do with rendering glitches is something you'll have to debug by eyeballing it, regardless of where you render your ui. There's no way of automatically logging misplaced floats.
P.S. There's also less to monitor. Typically you'll monitor for performance and security. Performance depends on the browser and pc specs, not the server's load, and security has nothing to do with the client. So, really, there's just not much to monitor. You can attach error handlers to automatically report exceptions to the server, but i've not had a need.