True, the SSD will make your system much faster overall, with better boot times, snappier response when loading programs and doing system access or caching. Fresh installs of OSs are always best, but you can clone your HDD to your new SSD, then swap boot order.
SSDs are best used for things that require speed, write cycles are not an issue (SSDs will reallocate defective sectors just fine, in the unlikely event you ever use any up) but just the price per GB is. If you need storage, get a normal HDD.