I've kept S. helianthus in the past and actually gave it to a friend of mine a while ago. It came in from a Caribbean shipment at the LFS. It was different and caught my eye. What really caught my attention was the excpetionally powerful sting and stickiness of S. helianthus. Unlike any carpet I've encountered before.
One of the Mertensii Carpets didn't make it unfortunately. The other seems to be relatively well but I'll wait a little longer before calling it a success.
I'm in the midst of acquiring a Purple Gigantea that I've sourced out and hope to have new Red Carpet for my upcoming build.
I'll keep you posted.