Just be clear, this WordPress plugin do not remove files from server - it's safe speeding up tool. If you accidentally break website appearance you can disable plugin and website will present old, unoptimized version. Btw: it's good approach to compare before/after timings :)
Gonzales is not another clone of WordPress performance plugin. So what’s the difference between this and other optimization tools? It truly gets rid of problem by excluding JS/CSS from HTML code while other speed up plugins mask problem only - they use compression/merging method to minimize website size. In fact such a website still loads useless files which affect website performance. If you conditionally disable plugins you will definitely see difference in document loading time, especially when requests cannot be cached.
Gonzales uses brand new way of WordPress optimization method which other plugins do not use. I don't want you to uninstall other awesome tools like Cache Enabler, W3 Total Cache, WP Super Cache or WP Rocket - Gonzales works with them symbiotically and you don't need to configure anything! Nice way to speed up WordPress, huh?
Well, you should. Even thought timings to all resources are the same you still forces people users to download the same large CSS/JS files. Once you use Gonzales website will be delivered faster to browser even with HTTP2. To verify if you use HTTP1.1 or HTTP2 use HTTP2 tester powered by KeyCDN team.
One of interesting options of plugin is silent mode. Once you complete optimizations you can switch Gonzales to work in background (disable menu and hidden panel). To do it define DISABLE_GONZALES_PANEL in function.php file of your theme. Thanks such a approach you will save preciouse top admin bar space and Kbytes in RAM.
There's long list of actions you must take to achieve great performance results but they need a lot of your attention. I suppose your time is precious and highly limited so here is what I recommend to read once you buy Gonzales: “How to move scripts to bottom with or without W3 Total Cache”. Hey, don't forget about PHP7 which is officially available since December 2015. Thanks new version of PHP7 you can get much better performance and depending on hosting you can enable it by adding one line to .htaccess or switching checkbox in administration section of hosting panel.
2.1.6 (2019-11-13) ▹ get rid of MU plugin error on front-end after 2.1.5 update 2.1.5 (2019-11-12) ▹ WordPress 5.3 support ▹ added RAM limit information for visited page ▹ fixed bug in MU plugin dependency checker ▹ fixed database error issue when tables are not created automatically ▹ reduced number of SQL queries ▹ removed group section if doesn't present any data ▹ unified panel appearance 2.1.4 (2019-08-27) ▹ added reset style for back-end to keep appearance the same regardless theme 2.1.3 (2019-08-20) ▹ added dependency checker in MU plugin in case of main plugin deactivation ▹ solved high SQL usage issue on some environments ▹ improved back-end appearance 2.1.2 (2018-12-06) ▹ removed "fatal error: allowed memory size..." ▹ WordPress 5.0 support ▹ improved panel appearance 2.1.1 (2018-02-15) ▹ added fix for FastCGI servers (when configuration is not saved) ▹ added support for older PHP versions in MU plugin ▹ improved script ("select" tag script wrapper controller) ▹ improved panel appearance ▹ improved plugin security (create Gonzales tables in database if not exist) 2.1 (2018-02-06) ▹ added plugin activation/deactivation control ▹ added regex filter for plugins ▹ added auto-update functionality ▹ added emoji control ▹ simplified UI ▹ improved assets dependency manager 2.0.4 (2017-11-21) ▹ added better support for optimization oriented servers ▹ WordPress 4.9 support 2.0.3 (2017-05-21) ▹ WordPress 4.8 support 2.0.2 (2017-02-25) ▹ improved appearance (CSS/JS improvements) ▹ removed unused quotation mark from page footer 2.0.1 (2017-01-03) ▹ added "Disable current URL" option ▹ keep Gonzales panel visible after configuration save ▹ improved configuration saving ▹ improved activation exceptions handling ▹ removed HTML panel code for non-signed in users ▹ added rule to ignore URL parameters (e.g. /contact?gc=39203 = /contact) 2.0.0 (2016-12-10) ▹ added content type filtering support ▹ improved usability ▹ improved disabling functionality 1.0.5 (2016-11-05) ▹ WordPress 4.7 support 1.0.4 (2016-03-10) ▹ improved HTTPS support ▹ added core cache clearing ▹ better support for older PHP releases ▹ WordPress 4.5 support 1.0.3 (2015-10-24) ▹ added short instruction after plugin activation ▹ removing PHP4 references ▹ adding switcher in code to enable Gonzales in back-end ▹ improving permissions check on guest sessions 1.0.2 (2015-09-30) ▹ added WP Rocket support 1.0.1 (2015-09-01) ▹ improved menu appearance ▹ increased number of controlled JS/CSS 1.0.0 (2015-01-30) ▹ initial commit