The number on the box describes the pump, not the puck

Four of these seven machines advertise a 15 bar pump: the Breville Barista Express, the Gaggia Classic Pro (an Italian-made Ulka vibration pump), the De’Longhi Dedica and the Breville Dual Boiler. Three of those four also publish the figure that matters, which is what an over-pressure valve lets through to the coffee. Breville gives 9 bar regulated extraction after low-pressure pre-infusion on the BES870, and an OPV limiting maximum extraction pressure to 9 bar on the BES920. Gaggia states the OPV is factory-calibrated to 9 bar on current-production Classic Pro units. All three land on the same number, 60% of the advertised rating. The 15 is the pump’s ceiling; the 9 is the shot.

That is why “15 bar” cannot separate these machines — the four that print it print the same value. The distinction worth drawing is between manufacturers that publish the regulated figure and one that does not: the Dedica’s page gives 15 bar and no separate extraction pressure, so a Dedica buyer has nothing published to check the shot against.

The other three approach pressure differently. Rocket publishes no brew-pressure figure for the Appartamento. Lelit publishes no pump rating or regulated brew-pressure figure for the Bianca either; its rotary pump feeds a paddle on the group head that adjusts water flow mid-shot.

The decision you cannot revisit later

Boiler architecture is how the machine is built, and none of the manufacturer pages here describe it as an option or an upgrade. Three arrangements are represented.

Single and shared: the Barista Express uses one stainless-lined aluminum Thermocoil for both brew and steam. The Classic Pro uses one lead-free brass boiler that Gaggia describes as dual-use. The Dedica uses a single thermoblock rather than a boiler. On all three, espresso and milk are sequential — the same heater changes job between them.

Heat exchanger: the MaraX and the Appartamento each run a brew coil through a steam boiler.

Dual boiler: the Bianca has a coffee boiler and a steam boiler, independently controlled.

What PID changes, and what it only reports

PID means the machine reads temperature electronically and holds it to a target. What sits behind the acronym varies more than the acronym suggests.

Breville’s Dual Boiler is the most explicit: two controllers, one on the brew boiler and one on the heated group head, holding water temperature to within ±1°C. The Barista Express publishes a target instead — 200°F (93°C), adjustable ±4°F in 2°F steps — which tells you what it aims for and how far you can move it, not how tightly it holds. The Bianca gives each boiler its own PID and puts the real extraction temperature on an OLED while the shot runs.

At the other end, Rocket states plainly that the Appartamento has no PID and that a pressurestat cycles the heating element. Gaggia and De’Longhi publish no temperature control method for the Classic Pro or the Dedica; the word does not appear in their feature lists.

For someone coming from a pod machine, the practical difference is whether the machine tells you its brew temperature.

The portafilter decides what you can bolt onto it

Portafilter diameter is a compatibility spec, and it is the quietest way a machine limits you.

The Barista Express uses a portafilter in Breville’s own size, supplied with single and dual-wall baskets. De’Longhi publishes no diameter for the Dedica.

If you never buy a basket, none of this matters.

The grinder is in the decision even when it isn’t in the box

Grinding is what the pod did for you, and it is the part of the setup nobody escapes. Gaggia, Lelit for both machines, Rocket and Breville for the BES920 all state no integrated grinder, and the Dedica takes pre-ground coffee or E.S.E. pods.

So six of the seven are half a purchase. That changes the counter space you need and how many decisions land on day one.

Where the machine stands, and what feeds it

Published tank capacities run from 35 oz on the Dedica — a figure from the Amazon listing rather than De’Longhi’s page — through 67 oz (2.0 L) on the Barista Express and 72 oz (about 2.1 L) on the Classic Pro, up to the 2.5 L tanks on the Bianca and the BES920, whose figure traces to retailer listings citing Breville’s instruction manual.

Plumbing is thinner than boiler count suggests. Rocket states it on the product page: hard plumbing water feed, no. Independent retailers describe a direct plumb-in kit for the Bianca, which Lelit’s own page does not mention. No plumb-in option appears in the documents retrieved for the other five.

Footprint separates these more sharply than any brewing spec. The Dedica is about 6 in (15 cm) wide. The Classic Pro is 8 in wide, 14.2 in tall and 19 lb. The MaraX measures 8.9 x 20.5 x 14 in (22.5 x 52 x 35.5 cm), and its published weight disagrees between sources — 18.5 kg (40.8 lb) on Lelit’s page, 53.0 lb on a US retailer page. The Bianca is the deepest and heaviest published, at 11.4 x 23 x 15.4 in (29 x 58.5 x 39 cm) plus the tank, and 60 lb (27.2 kg).

Matching the architecture to how you drink

Straight espresso, one or two shots, no milk: architecture barely enters it, and what is left is temperature control and portafilter size. The Classic Pro answers the second (58mm, 7-18 g baskets) and publishes nothing on the first.

One milk drink at a time, and the shortest path from pods: the Barista Express is the only pick that arrives complete, with its trade-offs written into the same spec sheet — a shared Thermocoil and a group in Breville’s own size.

Dual boiler is where brew and steam stop competing. The BES920 does it with two pumps, ±1°C and a published 9 bar OPV — everything fixed and stated. The Bianca does it with two PIDs and a paddle that adjusts water flow mid-shot.