My slant
Springer advantages:
Sits lower (better for shorter riders, sportier feel)
Better low-speed handling than Wide Glide
Wideglide advantages:
More legroom - better for taller riders
More comfortable 2-up riding (suspension-wise)
Engine better suited for high RPM operation
Springer frontend rumored to not hold up well
in harsh conditions (potholed roads, etc.)
Ideally, your friend should ride both bikes and make
up his/her own mind.