Generally a smaller engine is a more effective engine.
Also the use of fewer cylinders means less suface area per volume, which mean a more effective engine.
But few cylinders have a problem with balance, also if the cylinders become very large this means a long flamepath, and that isn't good.
With balanceshafts you can make a engine with few cylinders more smooth (usually used in 4 cyl. engines).
A V configurated engine is compact, and also allow a short crankshaft, but the forces created by the pistons i a little diffrent (sideways). An inline engine is easy to make stable, usually there is one bearing per cylinder and one at the end. The number of bearings with a not too long crankshaft makes theese engines very durable. But the differences in durability between engines is rather because of construction, than construction type.
But since diffrent types of engines behave, and sound diffrent this is a "salething", because there is probably nothing you can't do with a inline four that you can do with a V12.