Phillip it is easy to think that very complex textural sounding instruments are best in that area alone and not so good for more normal musical duties. But all these great instruments have a very straight and musical sounding bank of sounds and presets in there within their library.
Instruments like Native prism and Alchemy have incredibly complex and soundscape type sounds for sure but they are riddled with just great sounding straight up sounds. IRIS has them too. Your music and mixes would more than likely benefit from such use. The quality of IRIS may be better than some of the instruments you are using now and deliver a higher quality sound for normal sounds such as strings, pads, leads etc ..
The way to find out would be to load the demo and work with it for 30 days or so. The standard bundled library would be part of the demo package and I am sure you would at least get if you are going to use it. I think I am going to just jump in and go for it! The only thing for me is that I would not mind knowing how the Spectral editor in Alchemy compares to IRIS and if they are doing something very similar. Maybe
Jind might be able to answer that one more fully. I am fairly Alchemy proficient now with the player at least
(I have many expansion packs for it) and see the upgrade to the full version a compelling option for me as well.