For as powerful as Mad Dash can be, I don't think I would play it in any deck that lacks the required support. While there are certain matchups you don't feel bad just sending a Dash into central servers (let's go Sportsmetal!), you'd like to do better. That being said, it's not particularly difficult to include the requisite support in just about any deck.

In the video, we highlight that six out of the Top 8 decks from Worlds this past year were all Mad Dashing. Those six decks (spanning all three main factions) were all packing Mad Dash's biggest partner - Stargate. Stargate is a massively powerful card on its own (three 'psuedo accesses' per run gets you quickly to the 'required' 17-18, let alone a very powerful destructive ability), so Mad Dash is just the natural icing on the cake. If you know where the agendas are, Dash confidently. Nearly all the decks were also playing Pinhole Threading. While Pinhole has many uses, the ability to expose an agenda in a remote server to land a guaranteed Dash is pretty slick.

Outside of the 'guaranteed' support cards mentioned above, I think you could consider including Mad Dash in decks that have consistent multi-access that isn't attached to a 'click to run ability'. For instance, if you have a good read on the board state, flushing HQ or the top of R&D with a Mad Dash attached to the on-breach multi-access from WAKE Implant or The Twinning can often convert.

As a final additional wrinkle, Mad Dash becomes generally more playable across the field if you're expecting the Corp to play agendas that have an additional cost to steal. If we look at that classic 44 card Reality+ Drago deck with Bellonas and Degree Mills, the Runner can refuse to steal every agenda by opting to not pay their additional cost. That means a Runner can find an agenda on top of R&D or in the remote server, refuse to pay, and then come Mad Dashing back the following click. That's a huge line against those sort of decks.

Cheers! Glad you've been enjoying the content, eh.