There are many ways to improve performance but not all performance enhancements will be compatible with your website or hosting environment.
The best approach is usually to try out different combinations of performance enhancements, find the best improvements and test everything is still working on your website.
Minimising the number of third party extensions also minimises the likelihood that performance enhancements will cause an issue.
The performance features provided with your template are often the best ones to use as they have presumably been tested and work well with your template.
Enabling GZip is usually a good idea but does increase the load on CPU. If you are close to a CPU limit on your web hosting plan, this may not always be the best idea. There are usually resource utilisation monitoring tools included in your web hosting control panel (e.g. in cPanel) so you should be able to see the effect that enabling GZip has on CPU.
Other things to watch out for when enabling performance tools are:
- check that styling is unaffected (some utilities combine CSS files but not in the original order which may affect styling)
- check form submissions and CAPTCHAs still work