Originally posted by Kevinlee My Two cents worth.
If you plan on doing some slapping I don't think either the Corelli or the Helicore Pizz is the answer. I've tried Helicore Pizz and in my opinion they are far to lively (too much sustain) for slap. And they do seem a bit metalic sounding.
Yep.
If Bill finds old Spirocore too metallic, that means he need something quite warm. Corellis and Helicore Pizz are not the best choice, IMO.
A couple suggestions would be Jargar Dolce, Very Warm (for a steel string) no sustain really but for slap and bluegrass I think this is more the sound you would want. There is a bit of a waiting list right now I hear but the price is right around $100.00
Right!
I had Forte Jargars on but switched to Mediums a week ago, and I'm delighted!
Warmer than the Fortes.
The Dolce could be a little too floppy/thin for me, but for slap I guess they can be great.
Another string I've found to be fairly warm for steel and easy on the fingers is Helicore light Nickle Wound.
You're probably talking of the Orchestral Helicores.
Bill, for your information, Helicores are available in three kinds: Orchestral (warmest), Hybrids and Pizz. Each is available in three gauges, and the Orchestrals also in solo-gauge (thinner than Light).
And then theres the Eurosonics which some people hate but I'm actually rather fond of. They are very gut like in feel (BIG diameter) and I find them to be very warm once there broken in a bit. These are some kind of nylon or synthetic something on steel core. Easy to slap and good big sound for bluegrass.
I tried the G but didn't like it. Was too twangy.
But as you say, it may settle in after a while and be a great bluegrass string.
Obligatos are another option but I hear there life span is not that great.
Not recommended for slap.
Like the rest of us you will eventually spend hundreds of dollars on strings and from time to time be happy with your sound. 
Welcome to the club!