i can answer that, since i play edb in church complementing my regular fretted bass guitar.
the answer to your question is 'tone'. what are you really looking for?
a fretless bass has a 'mwah' factor which many bass players seek. the edb doesnt sound 100% like acoustic double bass (although close enough), in fact the tone is a class of its own (and still have the same 'mwah' factor like db). db and edb is more 'thumpy' and doesnt sustain as well as fretless.
thus selection is really due to the tone you seek. portability is secondary.
due to longer scale length in db/edb (41"+), you'll need to learn different fingering technique. string tension on db/edb is higher too (eg, G string is 65+ lbs, comparing G string in long scale 34" bass is about 34+ lbs). it can be painful at first (literally too since the action is so much higher), but can be overcomed.
arco (bowing) adds a different dimension to the bass tone. although not commonly seen in jazz, but there are many good jazz players who can bow too. am still learning to do this well.
ashbory is a good substitute for tone (almost gotten from rottenramone), but it has problems too. due to silicone strings, you must powder your fingers with appropriate powder to prevent string sticking to fingers. older ashbory is difficult to keep in tune. and the strings are hard to get in singapore.
visit zen guitarwerkz in peninsula plaza, they have stagg fretless bass AND the stagg 3/4 edb (the edb which i have). try play them to compare the tone for yourselve.