The advantage of the Stealth Head is:
#1. looks almost like a stock Head.
#2. Stock spark plug location will clear manifolds and headers designed for stock heads.
#3. Flow better than stock
#4. hardened Exhaust seats, No problem running Unleaded fuel.
#5. A lot lighter than stock.
#6. Affordable, not much more cost than rebuilding stock heads.

Disadvantages:
#1. Not made in the USA.
#2. Out of the box flow slightly less than the Edelbrock RPM.
#3. May need pushrod clearancing.

Unknowns:
#1. Customer service? I have not had any problems, but I have not tried to return anything.
#2. Quality issues? Some have posted on here about quality issues. I have no way to verify their issues. The heads that I have checked out fine, and I know several others who have had no problems with them either, but we have not torn down the engine to re-inspect the heads.

With the Stealth or Edelbrock heads you need to buy a head bolt kit that has the reduced wrench size bolts. The Angled spark plugs of the Edelbrock heads should provide a better plug location in the chamber for performance, but it can cause fitment issues with some headers and exhaust manifolds.
If you are going to run a solid cam, or really agressive hydraulic cam you will need to change out the springs/retainers/locks on either cylinder head. The stealth springs/retainer/locks should handle the same cams that the edelbrock heads do.

If you are looking for a performance head, and don't care what it looks like, you may be better off starting with the Victor, or Indy heads, rather then spending $1,000+ on the Stealth/RPM type heads then spending another $1,000+ to have them ported.