Tops are 95% cosmetic (especially on a neck through build). They can add to the overall sonic character by means of weight/density and how the combined components resonate with the string vibrations.
Pros: smaller/shorter instrument. They’re great for travel as they fit in an electric guitar sized gig bag. They work well if you find yourself on small, crowded stages (small clubs, coffee houses, orchestra pits, etc..). Sonically, they typically possess a more staccato attack which is great if you play anything percussive. They’re lighter and easier to wear on longer gigs.
Cons; the changing of strings can be a little tricky. They lack a little bit of the fullness and resonance you experience from a build with a headstock. On the 5 and 6 strings; the nut width is a bit wider than my usual spacing via a hand carved nut. This is due to the dimensions the hardware is made to accommodate.
One benefit of a thicker neck is a stiffer, more rigid/stable neck. Of course, this will only be the case if the woods used are properly aged & cured as well as constructed with proper grain orientation.
The lightest body woods I’ve used are Paulowina, Spanish Cedar, and the super light varieties of Swamp ash. They all work, but yield a softer overall attack. I’ve had my best tonal success (while keeping weight down) by using alder or hemlock. For fingerboards; the softest/lightest I’ll use is Indian Rosewood…..and that is rare. I gravitate towards more dense woods for fingerboards for both tone and functionality.
I use a three part mixture of teak oil, thinner and semi gloss poly. I use between 3 and 6 coats depending on the woods involved. Woods that are less dense or more open-pored tend to drink up a little more, requiring more coats.
Owners of instruments with this type of finish do not need to reapply this oil. For maintenance and cleaning, I recommend a product called Howard Feed & Wax. It’s great on the body, neck and fingerboard…..especially the fingerboard. Howard Feed & Wax can be applied either every 6 months or during string changes. You simply apply a small amount to a soft dry cloth, wipe it on, let it sit for a few minutes and wipe off the excess with another soft dry cloth.