I know nothing about their AR clone receivers, but I do know that their FAL receivers are not respected much in the FAL community. In fact, many FAL smiths won't even touch them. That reflects upon their other guns. I took a look at
http://www.hessearms.com and my latest Federal Arms catalog. Looks like that Hesse HAR-25 is running $1200 and the "modified FAL" mags are $45 each. Personally, I think you could do better in several directions. Not only does the rifle seem "iffy" since it's an AR-10 (even Armalite can't get them to be 100% reliable) and moreso that Hesse makes it, but also those mags! Your only supplier is Hesse, and they're expensive! Regular metric FAL mags are $8 each! Even USGI M1A mags can be bought for $31 each.
Get an Armalite AR-10 for only a few hundred more...it would be worth it, I think. Lifetime warrantee. Very accurate, and if it's breaking, you cna send it back.
Get an AZEX Arms or DSA built FAL for about $1200. Or get an Entreprise rifle for around $900. All these options carry a lifetime warrantee. Definately nice rifles and more reliable than an AR-10 anyway, although they might not be sub-moa accurate.
Get an M1A or build an M14 for yourself. You'll be $1100 to $1300 into it, and it will be reliable and you can also shoot DCM matches with it. Lifetime warrantees with Springfield and other rifle makers.
Looks like Hesse offers a one year warrantee with their rifles. I think you can tell I'm not crazy about the rifle. However, this is just my opinion. Good luck.