[sdiy] SMD experiences

[David G Dixon]

> Consider this: SMDs could be using the ground plane as a heatsink. 
> Through-hole devices will be generating (as everything does) 
> and also RECEIVING heat, via the ground plane.
> 
> Extra pads on surface layers can help dissipate that heat.

Good points.  However, referring to what I said earlier about how opamps
tend to oscillate more readily in SMD circuits at the same impedance levels
(which is based on observation, not on theory), and also remembering that
oscillation makes opamps run hot, it is then doubly important to try to
avoid in SMD circuits.