There's another difference to consider - back cutting.
Panel raising bits that also make the "back cut" say you
a set up and another operation. Horizontal panel raising bits
that cut not only the raised panel but the "back cut" as
well - at the same time - are available (Somerfeld for example)
whereas vertical panel raising bits require that you make
the "back cut" after panel raising.
If you get the right set - rail, stile and panel raising bit - they're
matched. Getting their set ups right can be a trial and error, time
consuming process - so I go with three routers, each mounted to
its own router table insert plate - each with its own zero clearance
fence insert - and sample set up block. If I need to make another
rail, stile or panel, I just pop in the already set up routers, install
the appropriate zero clearance fence insert - and start cutting.
Either way you choose to go - DO NOT try raising panels in one pass
and For The Love Of God - use a push block - or two and don't stand
In The Line Of Fire. It's not just the table saw that can Kick Back.