It's worked well for me in the past. LOL.
I'm with you, I certainly can't figure out Tesla at this point. It wasn't hard to see the upside when they were in the $30's, but I'm not sure now. The acquisition of Solar City is definitely interesting and actually plays into their overall business plan pretty well. It's just that they are really a quite unconventional company, so you can't really look at them like you would a regular auto manufacturer.
Their charging stations have solar panels, so Solar City fits in there kind of nicely, but more than that is the mass storage. Storage is the biggest pitfall with solar panels, and the most expensive part of a home installation. With Tesla's focus on batteries and their Gigafactory or whatever they call it, they could be positioning themselves to solve the storage solution and already own one of the biggest players in home solar installations and really corner the market and price others out. But, I'm not sure I want to count on that at $217 today.
Cisco is solid. Part of what I do these days is datacenter design and Cisco is THE major player in that market and datacenters aren't going away anytime soon.
As far as technology is concerned, keep an eye on Nutanix. I'm pretty sure you're a lawyer, so I assume you don't know much about virtualization and mass storage, but Nutanix is leading the charge with what they call hyper-converged solutions. Before, you would have a company like NetApp or EMC for your mass storage and then also have Dell or IBM or whoever for your servers to act as virtual hosts. Now they are combining all of that, server (and virtual servers) and storage, into one box. It drastically reduces physical footprint but also great reduces recurring maintenance costs. Nutanix is leading the way, but there are others jumping into the fray.