We have offspring who have one of these. He's 'into' coffee, roasts his own green beans etc. I sort of watch him do his barista thing on a visit a few months ago. I thought the end result was comparable to stopping it at the neighborhood coffee shop.
That said, any espresso machine that produces sufficient 'bars' of pressure to push water through the ground-up beans will produce espresso. Somehow I can't see how a $500 Sirena is any better than a 'no-name' $150 machine. BTW, this one is based on a Saeco design.
I have a Capresso combo machine that's actually 2 separate systems, separate water reservoirs, heater elements, etc. It has performed flawlessly for 7-8 years though the carafe dribbles on the counter if you try to pour the first couple of cups too fast. The espresso side also has worked flawlessly and makes anything I'd order at Starbucks.
Jim Ricks