Manufacturing industrial-volume composites with well controlled uniform dispersion can be challenging, and is especially true for high performance polymers, such as polyetherimide (PEI). Toward that end, we report here a simple and versatile 2-Step processing approach which is based on formation of a high concentration of multi-walled carbon nanotube (MWCNT) filled PEI, which we call "Solid Nano-Nectar" (SNN). In this study we found surprisingly strong influences of the solvents that were used in the SNN preparation for dispersion of MWCNTs on the properties of the composites. The thermal conductivity of the SNN (made using DMF solvent) incorporated composites was about 72% higher than pure PEI, and 50% higher than that from 1-Step processing at same loading of 0.5 wt%. The thermal stability increased by 13 degrees C from this composite prepared by 1-Step processing, but a more noticeable change in thermal stability of 33 degrees C was observed at same loading using the 2-Step process. Such improvement was also observed in dynamic mechanical properties.