What's 'wrong' with manufacturer's chargers

I am just looking into rechargeable batteries (for flashes, what else!ops I figure this is a way to get started:

Eneloop 4 pack + charger

Everything I've read though makes me feel like I should rush right out and buy a fancy expensive charger.

Is there anything particularly wrong with just using the manufacturer's charger? (included in the bundle in this case)

There are better chargers than the OEM models...but they are an added expense. Studies have shown that better chargers can add to the life cycle of batteries, but you have to decide if the additional expense is covered by the additional life...for me, I didn't think it was worth it. I use the OEM charger and have a set of Kodak batteries that are over 10 years old and still work perfectly.