The notion that any Chromebook would be a "full substitute" for a Windows PC is entirely dependent on what you do with your computers. If you are producing a lot of video by editing with your computer, modifying images with Photoshop, or if you are a tax accountant by trade and need to run your tax-return preparation software, or if you are an engineer / draftsperson who does complex drawings, architectural renderings, etc. for a living, then a Chromebook will not be a full substitute for Windows.
So your first step would be to use your Windoze PC to bring up the Google Play store and see if there are software applications there that will provide you with the functionality that you need that goes beyond internet browsing, reading books, playing video or music, doing email and other "standard" stuff. You can use any banking website from the Chromebook that you use from any other device with a browser. And now with thousands of Android apps available for the Chromebook, you actually have more choices of apps than you do for a Windows environment. For consumers, there are two key Windows apps that may prevent one from completely abandoning Windows. Those apps are Quicken for your financial management, and your tax preparation software (TurboTax or HR Block TaxCut or Tax Act for example). But there are multiple companies working on making it possible to run these apps on a Chromebook by the end of 2019.
If you are a software developer writing code for Mobile or Progressive Web Apps, then a modern Chromebook like this would be an excellent dev platform. With the direct access to Linux that's in a sandboxed environment, you've got a very strong capability to setup your desired Integrated Development Environment (IDE). This HP x360 has 8Gb of RAM, which is important if you do indeed plan to heavily use the Linux environment along with your Chrome OS and Android apps.
This Chromebook is a very good value if you can pick it up for $450 or less. Like with any current Windows or MAC Laptop, you'll need to spend $30 or so on a USB-C dongle that gives you an HDMI port and an extra USB-A port so you can hookup an external screen and more than one USB accessory device. FULL DISCLOSURE: I've had an HP x360 14 since the beginning of 2019 and I love it. I don't miss the 45 minute waits for Windows updates to complete, I don't miss the slow boot-up and shutdown of a Windows laptop, nor do I miss the need to spend $70-$90 / year for firewall, anti-malware, anti-virus security software that's required on a Windows PC. If I need Microsoft Word or Excel etc. I can subscribe to Office 365 just as with a Windows PC. Or I can run free Office software from Google, or use LibreOffice on Linux (which I do now).
Try it out. The learning curve is not steep, but the rewards are plentiful