I use a Dremel variable speed motor tool I've had for about 35 years. It is 120volt cord type. Not much it won't do. The cord is a pain sometimes when working on the layout as it gets in the way or manages to get caught on buildings and other things. If I bought another it would probably be cordless for that reason only. One advantage to the cord job is you won't forget to charge it which only happens when you really really want to get something done and the battery is kaput. Either way buy a good quality motor tool and it will last a lifetime.
I have both the Dremel 4000 and the Stylus. I use the 4000 for heavy jobs, and the Stylus for everything else. It's cordless and there isn't much it won't do. The battery lasts a long time, not like the older ones. Put it in the stand/charging station and it's always charged. it's on my workbench at my right hand, and I've never bveen caught without power.
I have the cheapest Dremel. I got a keyless chuck for it. That saves a lot of time. I have it plugged into a lamp dimmer switch for speed control. It works great.