I think in total, DW wasn't a very good GM in that he wasn't a very good team builder nor did he do much to build a top notch front office team but he had some of the biggest home run moves of any GM which really carried him far. Thornton, Burns, Boyle, etc were core additions that can carry a team for a long time.
I guess the last couple years like picking Kane over Pavs or signing Labanc to a big extension after flubbing his bridge year soured me but I always had issues with him not being able to bring in good depth. Some of the best depth we had just felt like luck working out like Donskoi being pretty good or Torres being shockingly good after we tossed out Murray and Clowe during a retool.