For me, it boils down to subject matter. My stash probably has at least one kit by every manufacturer. Every kit manufacturer has it’s own quirks that I know I’m going to have to deal with. MPC: The bench will probably be covered in flash and styrene dust before it’s all said and done. AMT: I’m more than likely going to fill a hole thru the engine block and rework the front suspension. Moebius: Installing the glass will require a dexterous, surgical touch. Etc, etc.
i have a few curbside kits that I plan to cut open for customization (Atlantis ‘57 Caddy, AMT ‘59 Imperial and ‘64 Merc) but I tend to stay away from curbsides.
Some of my favorite building experiences and (I say this humbly) best looking models have been MPC “trash” kits or other kits deemed challenging enough for some to avoid like the plague like the Revell ‘59 Skyliner.
The parts count on a particular kit has no influence on whether or not I’ll purchase it. That said, sometimes I’m in the mood to deal with a bazillion parts and sometimes I’m not (looking at you, Testors Porsche 356.)