Get unlimited texts or text using apps?

I'm getting an iphone 5 soon and my dad recommended that instead of getting the $20 unlimited text bundle, that i download one of those free text apps that let text for free. And i have used them before and they are ok but than i would have 2 different phone numbers and they are not very good, they lagg and sometimes drop texts. Also i think it is better to use the original messages app from the iphone. But than again $20 a month that can be saved is really good

what should i do? What do you recommend as far as apps?

please don't tell me to switch over to a different carrier or get prepaid or anything like that

When you get your phone just make sure imsg is turned on first (mine was off by default so you turn it on in the settings), that will make any normal msgs you send to other iphone users free, it won't count against your plan. I do the $5 for 200 msgs a month and never go over it but most of my msgs are imsgs.

Try Google Voice - it allows texting "for free" without all of the "junk" you get with other apps.