My 2 cents comparing a Lincoln AC225 (AC only machine). to a Miller Thunderbolt AC 225/DC150 is that the Lincoln welded a microscopic bit better comparing the AC side of each unit only. Additionally my Lincoln had like an industrial type cooling fan in it compared to my Miller's rinky dinky little fan which is borderline cheesey. In my case I kept the Miller since it had DC.
That all said, I would keep the Hobart in this case for the extra amps it puts out on DC side (160 compared to 125 on DC) which will be helpful if you ever run any 1/8" diameter 7018 rod. Additionally, the fully adjustable settings of the Hobart should be a slight advantage over the tapped settings of the Lincoln but only a real skilled welder is likely to notice the difference on this type of entry level machine.
This all said, with both machines at your disposal already, then I would think that you should know by now which one you prefer using for your uses. I would keep the one you like using best as both welders are so similar in capability that the differences are small. (e.g. If I rarely stick a rod with one but am always stcking a rod with the other? I lay good beads with this one but struggle with the other? Keep the one that works best for you and your uses).