PT Boats

"However, depending on the campaign, it may be worthwhile to have locally
strong FTL capability for regional attacks, while leaving mostly system boats
in defense most other places.>Level 1 Shields"

System defense is definately the focus of the small SMR armed boats
in the campaign I run -- small borrowed bits of the Tuffleyverse with a
little bit of H. Beam Piper's Space Viking and a very convoluted dash of
victorian sci-fi (just the feel, not the actual technology -- no maxim
guns
in space or anything,  more like the movie Dune: the guns are sci-fi but
the set dressing is oddly 19th century.) Sort of took the turn of the
century sitiuation of a half-dozen sparring  "Great Powers" plus
emerging powers (the US, Japan) plus lots of colonies and minor neutrals and
transposed it into space (even used an old 1914 copy of Janes' Fighting Ships
as a starting point for fleet strengths etc.).

As for the missle boats they're popular with weaker powers as an equaliser for
system defence (following the precedent of the French, who
built nearly 200 small torpedo boats in the 1880's-90's) as well as a
popular export item that winds up being the major component of fleets for
minor neutral worlds. In the Tuffleyverse I'd say they'd be popular with the
third tier powers: PAU, LLAR, Islamic Federation etc.

                        -M