a 3-group linea pb makes sense when your bar can use a third brew position during the rush and the site can support the larger machine. it is a workflow choice before it is an upgrade.
three groups give you another place to brew. they do not give you another barista, a faster grinder or more room to finish drinks. before buying, find the part of service that is actually holding the line up.
look for a waiting portafilter
watch a busy service and record where orders wait. if coffee is ground, distributed and ready but both groups are occupied, a third brew position may help. if the groups are frequently empty while the barista handles milk or takes orders, adding another group leaves the main problem in place.
count espresso orders and the shots needed for them. look at the busiest periods rather than an average across the whole day. a cafe with concentrated demand has a different equipment problem from a cafe with the same sales spread over many hours.
include the menu. extra-shot drinks, decaf orders and a large share of milk drinks change the work. do not use a fixed weekly quantity of beans as the only signal that you need three groups. that number does not explain when the coffee was served or how the bar operated.
decide who will use the extra position
sketch the working positions behind the bar. where is the person grinding? who handles milk? who finishes and hands over drinks? can two people reach what they need without crossing each other's work area?
if you want a third person on the bar, plan that person's job. three people standing in front of three groups is not automatically a useful layout. the grinder, knock box, milk storage and pickup area can still create a shared bottleneck.
i would walk through the layout with empty cups and pitchers before signing off on a new counter. that is easier than discovering a bad handoff after a heavy machine has been installed.
check the larger footprint and load
la marzocco usa's current linea pb sheet lists the 3-group at 37.5 inches wide, 23.3 inches deep and 21 inches high. it lists a weight of 205 pounds. those are us planning figures to verify against the exact configuration being ordered.
compared with the published 2-group dimensions, that adds 9.5 inches of width. decide what moves out of that space. if the larger machine pushes the grinder or pitcher area into a bad position, the extra group may cost you useful working room.
counter support, delivery access and service access belong in this check. measure the route into the space as well as the final position. ask the installer what clearance and access the finished bar needs.
do not assume the same circuit will work
the us sheet lists 208-240 volt single-phase power and 50 amp service for the 3-group, compared with 30 amp service for the 2-group. it also lists an 11-liter steam boiler and a 5-liter brew boiler for the 3-group.
those specifications do not translate into a guaranteed number of drinks per hour. they also do not tell you whether your existing electrical installation is suitable. have qualified people check the specific machine, circuit, water and drain requirements before committing to the equipment or construction.
include the grinder in the decision
if one grinder cannot keep up with the planned service, a third group may spend time waiting for coffee. choose the grinder around the rush, menu and dosing workflow. if decaf needs a separate grinder, make room for it now.
ask to see the proposed workflow as a complete station. the machine and grinder should be selected together, even if they are quoted as separate items.
if the third group is only for "later"
make that future plan specific. expected staffing, menu and peak demand are more useful than an undefined promise of growth. compare the space and installation consequences now, then choose what you can actually use.
for a 3-group linea pb in los angeles, couplet can help work through the configuration, grinder pairing and bar plan. start with your busiest service, then build the equipment around it.