A one-piece cue has no central joint, giving it a straightforward construction. A two-piece cue travels and stores more easily, and its shaft can be replaced separately; the joint does need clean, careful handling.
For apartments, club travel and tournaments, the two-piece format is often more practical. A one-piece cue can be comfortable at home if you have safe storage. Check section length against your case and luggage before buying.
Assemble and separate a two-piece cue several times. The joint should close smoothly without wobble or cross-threading. Choose for your routine, not for the prestige of a format.