[Kirby64]

No offense, but we're not really comparing different things. You're offering an espresso machine that fundamentally has:

* No heating control

* No tank/water storage

* No milk frothing capability

The obvious comparison is a manual (lever) espresso machine that does not offer its own heating capability. It offers pressure control (via your arm) just fine.

Also, besides noise complaints and possibly some questionable reasoning involving vibe pump longevity, I have yet to see a compelling reason a rotary pump is better. They're 'nicer' and offered in higher end stuff, but performance wise a very good vibe pump seems just fine. Flow rates are more than adequate for pretty much any normal brewing method.

Regarding 51mm vs 58mm: you might be correct technically, but the ecosystem around accessories is firmly in the 58mm camp. As far as I can tell, the difference is so marginal it doesn't really matter anyways. Puck prep and other things will matter more for the average user.