Lighting Question LED or MH

I previously have used CFLs but I am looking for a better yield. I am in between ordering a 400 watt MH or getting into LED lightning. This will be used in a closet so I am worried about generated heat.

MH with good ventilation, no experience with LED's myself but i have never seen anything under leds that looked inpressive, If you can vent at all maybe t5's ?

stay away from led`s. they haven`t been proven yet and are to expencive. an hps would be the best choice if your only going to buy 1 bulb. it is ok for veg and good flower. or do switchable ballast then use both mh and hps bulbs in it. the only thing you need to do is remove the igniter from the circuit.

I would would go with the MH over leds and HPS over MH if you only going to get one. If heat is an issue for you make sure you get a reflector that you can hook up a exhaust fan to or just get a cool tube for the lamb.