Harman Kardon AVR vs. Yamaha RX-V2400 ??

I vote for Yamaha because it's good for both music and HT. You can read the following thorough articles:
Review by HTM and Review by GDS.
Good luck.

While you're at it, check the Denon AVR-3803.

I personally like the newer H/Ks, you can get the AVR430 for less than the 7200, it looks better, and you can use it's preamp outputs later if you wish.
If I don't get a hgih end pre/pro soon I may just get the 430 and pair it with some form of multi-channel amplification, as the amps in it are weak and can cause music to sound a bit strained, especially at reference levels.

I'm bias. Go for THX RX-V2400. THX may be meaningless on A'gon, but to mass consumers, they dig it, so resale value and foot traffic may be higher.

Do yourself a favor and look into used separates if you value sonic integrity(and to me, sound is everything in an audio system)!
The Outlaw audio 6/7 channelx100 amp and pre/pro would only run you %1500 together!..the sound blows away any receiver at that price period!..and it has 24/192 dac's, dirrect analog inputs for sonically pure connections, and built quality is that of a tank, and customer support is excellent!
You can buy a recevier, but you will get(I know, I've sold everything on the market in 6 audio stores over the years, and do custom!) less than 40% of the sound qualtiy, maybe less! To me, it's not worth it. Thos speaker can sound soo good...why skimp. But, that's me.
If it where my money, the Denon at that price is better. I like Yammie's, but only used as a pre/pro, and adding power amps from the pre-out's. Processing is good enough.
Again, used separates(like old Acurus ACT 3/100x5 power amp or Parasound AVP1000 and HCA1205 used are about what you would get the AVR2400 new..sonically however, it's no contest...so you might consider.
I know everyone is inlove(why I have no idea) with receivers, and they have their place indeed. Still, if I was spending $1k-$1500 on amp/pre/pro, I wouldn't hessitate to do separates..every time...the sound is leaps and bounds a
ahead..if that's anything too you anyway