Is it easy to bog down the client with the extra processing?
Sure, if you're not careful; but that's the case w/any language or layer of an application stack. I'd consider becoming familiar w/JavaScript a greater concern though. Learn to avoid JavaScript's foot guns, and use tools like Speed Tracer to help profile your JavaScript.
If it matters, my time tracking and invoicing product uses heavy client side processing, to the point where some of its reports never touch the server. We're seeing response times in the low ten's of milliseconds when relying on JS-only generated reports.
Makes sense, there's no one answer to my question, because there are so many variables involved. So, it will take trying them out and of course it will depend on my needs. It may even make sense to do server side on some parts of the site and client side on others. I like the idea of being less constrained to my backend technology, which is what attracts me to JS MVC. I also like how concise Backbone.js is, it doesn't seem to try to do too much.
Sure, if you're not careful; but that's the case w/any language or layer of an application stack. I'd consider becoming familiar w/JavaScript a greater concern though. Learn to avoid JavaScript's foot guns, and use tools like Speed Tracer to help profile your JavaScript.
If it matters, my time tracking and invoicing product uses heavy client side processing, to the point where some of its reports never touch the server. We're seeing response times in the low ten's of milliseconds when relying on JS-only generated reports.