I've decided that I want another AR.  I'm in the planning stages and need help on barrel selection.  I'm looking at 14.5" with a phantom suppressor, but I can't decide if I want an M4 profile or an Hbar.  Aside from weight savings and the fact that it looks cool, I am not aware of any advantages of the M4 profile over an Hbar.  What do you all think?  Just so you know, I am also planning on A2 top end as this will be my basic plain jane, no-frills, vanilla rifle.  Thanks.

Edited to add:  Are there any advantages to an M4 profile over an Hbar?

M4. Much lighter. Also check out CMMG's 14.7" w/A2 FH.

Well, the M4 is 1/2 lb lighter than the HBAR, but it's not near as noticeable with the 14.5" as in the 16" and longer barrels as the weight difference is primarily is under the short handguards.

This particular 1/9 CL HBAR (originally a dirt cheap A2 Bushy AK HBAR) shoots 1.25 MOA with Q3131A, and sub MOA with 55 grain Ballistic Silver Tips, is very handy and balances well with either the pistol or forward grip.  It may be 1/2 lb heavier than the M4 models, but it's POI doesn't drift at all,  and it's still dead on screaming red hot.
Since it's exclusively a 55-62 grain blaster, I have no interest in replacing the barrel with a 1/7 twist model, but one day I'll have to see what it does with some 68/69 grain match rounds.

The answer to your question either a M4 or HBAR barrel depends on how you are going to use it.

If you will use it by moving around and carrying it for a long time the M4 is lighter and a good choice.

Disadvantages of the M4 is it will heat up faster when firing at a fast rate and make your accuracy worst, but the advantage is that it also cools down faster than an HBAR.

If you won't be lugging it around much the HBAR would be fine. You could fire at a fast rate without overheating the barrel and it will have better accuracy than the M4. Disadvantage of the HBAR is it cools down slower.

The weight difference are all under the handguards, the HBAR approx. 0.8" to 0.9" diameter while the M4 is approx. 0.64" dia. under the handguards.

I have a 16" M4 tactical CAR, a AR-15A2 M16A2 clone (plain no high speed stuff) and I'm currently working on my mid-length 16" mid-weight RECON style CAR.

Pics of my M4 & A2 link

Quoted: Is a 14.5" m4 barrel with a Phantom going to reach 16" or are you registering it as an SBR? personally I'd get a 16" barrell. LMT (and others) make 16" m4 barrels, that way you can swap around flash suppressors (not that I ever bother to do that) without having to worry about them being permanently attached.

I have a RRA Middy with a 16" bbl already and wanted something different.  I guess I though that a 14.5" with permanently attached suppressor would bring it up to legal length.  

Thanks for the replies.  You have pretty much confirmed my suspicions.  I was just making sure that I didn't miss anything.