Im guessing UK/EU? I have the breville instance, had 3 of them.

1. Barista express...loved it had it for 7 years, consistent easy. - upgraded as i was seduced by the fancy new gen of machine.
2. Oracle - because i didn't want a digital screen but i wanted everything else. I got very inconsistent coffee over and over, i could pull 5 shots in a row and all would be different. Sold it after 18m.
3. Barista express again. The dosing collar helps with the mess aspect.

I never use the single wall filters, always the double...but i drink the same coffee every day. And can i suggest https://scoutcoffee.co.uk/products/rhino-shot-glass-2-4oz-70ml-with-spout-and-handle you will see in an instant that your shot is the right volume/colour etc the handle helps your fingers and the duel spout is convenient. There are lots of cheap alternatives but i have had one of these for 10 years. Use it daily, nothing compares.