Generally speaking, Windows 7 runs fast and efficient as is. turning off services, and uninstalling things can often just lead to slower overall system performance.
As far as being bloated, I don't think so. Besides, hard drive space is quite cheap. If you want to reduce the amount of disk space used, my best advice is to install 4-8GB of RAM, turn off the pagefile and eliminate the hibernate file (powercfg -h 0ff).
Linux distros are often smaller, no doubt about it. And they cost a lot less as well. If you are comfortable with branching out and trying something new, by all means give it a shot. If I recall correctly, Ubuntu takes about 4.5GB of space, while Windows is going to consume about 8GB.