I would say that most times cable>dsl, but not always. In high density population areas, dsl is usually a more reliable and faster option. Also, if you are on VDSL2 at high speeds, there will be no discernible difference and dsl can often have a lower sustained latency, resulting in a better (more consistent) ping for gaming. Cable tends to.... game the numbers with "turbo" features that are engineered for speed tests and little else.
I used to work for CLink, back when they were Qwest. For Meridian, here is how it works:
Depending on the technician they send out, if you go with a basic upload package of ~768kbits, you could be on old ATM or slightly less old aDSL. However, when you get the 5mbit upload, you get VDSL2. VDSL2 is a much more efficient protocol and tends to have higher consistent throughput. Every package that CLink sells will be based off of their technological availability. Get at least 7mbit, and you will guarantee you are on aDSL. If you want to use the VDSL2 tech (it is better), go for a 7/5 or 12/5 plan. There are no caps in place with CLink. I believe their contract states that there can be, but there are none in place as well as no tools with which to monitor them for front line service folk.
If you want to really think about the fun stuff, there is a 40/5 plan as you mentioned, but also a 40/20.
But, for each of the technologies that CLink uses, you need a different modem. Go VDSL2, buy the modem, call it a day. Also, you can downgrade your service to 7/5 if it gets too expensive. You only violate the ToS by cancelling. A downgrade is not a cancellation, so you will be fine. There is also a VERY important option to get called Linebacker. It insures the wiring in your home (your responsibility). If you get a phone line, get this in the package! Easiest insurance ever. I've seen wiring jobs that require a new fishing of copper.... the repairs were close to $400. With Linebacker, the max out of pocket (was) $75. It covers the lines and jacks in your house. Otherwise, CLink will only guarantee to the drop (the box outside your house).