Lithium conducting garnets such as lithium lanthanum zirconate (Li7La3Zr2O12, LLZO) are of great interest as ceramic solid electrolytes for solid-state lithium-metal batteries. Various synthetic approaches have been investigated for LLZO such as sol-gel, co-precipitation, thin film deposition, spray pyrolysis, combustion, and molten salt synthesis (MSS), not to mention the standard solid-state reaction (SSR) method. Most of the aforementioned methods have been used to form LLZO electrolytes with high ionic conductivity and density, each with benefits as well as some drawbacks such as cost, high processing temperatures, complexity, or difficulty of producing fine powders for thin films of LLZO. Further, there are many discrepancies between important performance parameters such as ionic conductivity reported in the literature, implying that achieving the highest performance is not completely straightforward and that the details of the synthetic route have substantial effects on the resultant materials properties. Herein, Ta-doped LLZO of nominal composition Li6.4La3Zr1.4Ta0.6O12 is investigated as a representative example, and is synthesized by various MSS routes as well as SSR for comparison, covering a wide temperature range (as low as 400 °C for MSS and up to 1000 °C for SSR). By using different synthesis methods for the same target material, the differences in ionic conductivity, sinterability, and other properties as a result of the peculiarities of individual synthetic approaches are investigated. Interestingly, elemental inhomogeneity on the order of individual LLZTO grains is observed to varying degrees in each of the synthesis methods investigated, with more inhomogeneity correlated with reduced performance in sintered LLZTO, implying that strict control over garnet phase formation is required to achieve optimal performance. Some advantages of MSS for LLZTO are presented and the thermodynamic and kinetic origins of compositional inhomogeneity are discussed, as are solutions and strategies to mitigate this inhomogeneity.