There are only 3 things required of a good work horse:
a) must perform well\
b) must be as reliable as possible
c) must be "nice" to use.
(SM Lisa was/is a recalcitrant coffee burner so doesnt satisfy criteriaion a) to start with. And why would anyone waste time *modifying* that when it can be simply and quickly and immediately (without time wasted) moved aside and replaced by better equipment in that regard.
After that once any commercial espresso machine goes into any cafe, its really up to the expertise and whims of any particular operator. There are plenty of sloppy operators, inexpert operators, expert operators and primma donnas. Actually the expert operators, in addition to the high end type of cafes that may justify the cost of a machine that really does deliver more (and can use it), are in the minority. The majority of cafes where most of the coffee is used, are not that type (although many want you to believe they are...).
There are a number of LM machines of various ages and models in my immediate market, that have a higher percentage breakdown rate than many "regular' brand machines. And as some of you will know, there is quite a difference between the various models (ie they are not all the same...). Regardless, many operators couldnt make a decent cuppa no matter what you put on the bench in front of them. The original 1961 Faema E61 machine still today (examples well looked after etc), makes a fantastic cuppa and performs well in all areas....better than many el cheapo modern machines. If you do a blind tasting between a Faema E61 and an original Linea, what will it prove, when 95 % of all coffees in this market are milks, however trust network marketers, cyclicly talk up the theoretical attributes of LM as if it were some kind of god that delivers SIGNIFICANTLY better coffee. It would want to, for the amount of hoo haa AND the price difference when you have to buy one. The Faema E61 is a classic, but not all of the miriad different brand and model modern E61 clone machines are so...... What does any of this prove?
Every commercial espresso machine no matter what brand, has only a finite service life before it is clapped out and starts getting heavy on the maintenance or should be changed out. In a busy cafe, that life is not long. Yet some comments would have you believe that LM brand machines magically outlast all else (my words)... they ALL wear out and become unreliable.
There are some really (really) great multi boiler PID machines from "regular" brand names now that are very reliable and deliver the goods (excellent cup, consistency).....but havent had the "treatment" that the LM brand has had so that they can justify their prices.
After the marketers have done the job on a brand name and have started to command the price they want for their "brands", it becomes a real hard slog to provide equipment that is being demanded by primma donnas because they think it will do something very special for them, on equipment contract basis which is what 90% of all commercial coffee market is in this country. On the one hand the clients want the best coffee for the lowest prices, then they also want the most expensive equipment to do the same thing they can do on machines that cost someone else considerably less to place... more cost, longer contracts, higher priced per kilo coffee to help pay for the equipment. It cant help but go round in a circle like that, and there is really only 1 party that wins.
That said....and I think I may have said above, that there are some excellent semi commercial espresso machines that can be had for around or under 3 thou these days that really are great performing, reliable machines. Those that reckon they can justify paying the sizeable premim to buy something else because they think it can do something special for them that nothing else can, are very welcome to go there but in the end my opinion is they are just paying a hellova premium for an extremely well marketed tin badge and their two cups of coffee in the morning