For the sake of completeness, the Synesso Hydra
has a "4 stage pressure ramping" feature similar to the La Marzocco EP. Based on the demonstration at the SCAA conference, Synesso's approach to brew pressure profiling seemed less complicated than La Marzocco's.
It is much less complicated. There are 3 pressure settings (line, pump, and pump with secondary bypass). You set the pump pressure like any rotary vane pump espresso machine (the bypass valve on the pump body itself). In addition to this, there is a second bypass with a needle valve and a solenoid valve on it. This one can be opened as an "intermediate" pressure. You can set it from anywhere between line pressure and pump pressure, though I am not sure how close to line pressure you can come with the pump on, even with the valve wide open.
Anyway, the control does get a little confusing because they left the paddle on the Synesso as a 3-position control (off-line/bypass-pump, from R to L) rather than going to a 4-position. This is slightly annoying, because in manual mode the middle position is line pressure ONLY until you enter the pump position. After you've entered the pump position, returning to the middle position becomes the bypass (rather than line) position. This is slightly convoluted IMO, but in practice isn't terribly limiting, with one exception: It is kind of nice to be able to enter bypass mode after line-pressure preinfusion as a very short (say, 1-2s) intermediate between line and pump pressure. This smooths out the pressure ramp-up a lot and seems to make the system a little more forgiving. If you want to make the machine act like this, you have to program it on the remote. It's trivially easy, but you lose the manual control over preinfusion time when you do this.
decided nod at the Synesso. It's just so much more repeatable and so much easier to use than anything else. The Strada EP I found extremely difficult to work in manual mode—even less usable than my own setup at home. The throttle is just too short for such a wide range of pressures, and the digital output I found much more tedious to read than a gauge. It might be great in programmed mode (i.e. on replay) in a shop, but I thought it was just horrible for toying around. The Synesso also has an easy nod in having its profiling system being very mechanically simple and easy to service (I've actually done a little bit of servicing on my friend's 1-group, so that's very much a firsthand comment). Sorry if that's terribly off-topic.