I personally think its a myth whoever stated the overhead system with a digital system doesn't work., there are several points I like to make regarding the overhead system:
a.) I've been running it for 40 years with power from the overhead system
b.) I have not yet noticed the wear of the pantograph wiper or the wire itself
c.) to construct the overhead wires in a professional manner does give you all the safety checks you need.
d.) I think it has more to do with fear than facts having the pantograph up
e.) the cost is of setting up an overhead system is expensive.
f.) using the Sommerfeldt system is a good start
g.) using the Märklin system and any other manufacturer is also ok and much cheaper but doesn't look prototypical
h.) unfortunately some loco manufacturers don't produce proper pantographs they are either prototypical and very thin or the spring which holds the pantograph up is to weak and I think the reason behind it, they are just made for show and not for operational purposes.
i.) Märklin pantographs are very sturdy and functional.
j.) some loco manufacturers don't have any electrical contact between the pantograph and the electrocnic circuit board and you have to establish your own connection.
k.) I find it odd having an electrical loco with its pantograph down, its a petty some modellers don't go the extra mile to install a proper or functional overhead system.
l.) As Eric mentioned the next best thing is having it just below the wire.
m.) some modellers also use a technique having the pantograph up and when entering or appearing from a tunnel they have the wire upwards within the tunnel and the pantograph than adjust itself to height .
n.) In my case I buy electric DC locos and this gives me another axle with rubber tyres
o.) the contact between pantograph wiper and the overhead wire is more reliable than that of the middle contacts especially over turnouts.
p.) you also could run your electric locos on a different power system
q.) you have the option to run if off the slider (power) but have the pantograph up at the same time
r.) or you could run your 2nd loco (push) power from your first loco via electrical couplings without the slider but with the pantograph up (no power)
s.) the same goes for consists of 2, 3, 4 locos or more
t.) you will rarely have a short (track) unless the loco or carriages derail.
u.) sometimes DC locos are cheaper than AC locos
v.) you can create sparks via pantograph and the overhead wires (led) or natural
x.) to set up a proper overhead system can be very time consuming and complicated when power comes from the overhead system
y.) much simpler if the pantograph is up but no power comes from the overhead wire and the slider is used
z.) I've given you 25 examples of why it is possible to create a more realistic scene
John
4 locos hauling a 50 carriage iron ore train