My first thought is that this design takes up too much real-estate.

With "THUNDERHEAD INVESTMENTS" as one continuous strings - of two long words - there is no way you'll be able to fit the logo and the company name onto anything other than a wallpaper without taking up or exceeding the width of the screen, paper - business cards, booklets, etc. If your client preferred it being long like that, then you could give them this explanation, if you think that may help.

- I'd make the font size a bit smaller, and either "THUNDERHEAD" or "INVESTMENTS" being a different colour. With all the words plus the logo being the same colour, plus the background, with no colour palette makes it kind of too muted to look at. Possibly a lighter grey.

- I'd put the logo above the company name, perhaps starting above the H in THUNDERHEAD. It's thunder, and it's above, so it makes sense to have the thundercloud above the word.

- Your mountain logo itself doesn't really signify a mountain fully, or a thunderbolt. I kind of think of a stock market line and an illusion triangle. I'd invert it possibly so it's dark on the inside and light on the outside. That way you can create a bolt out of a bold, solid lines and use the light gray from your palette for the outside borders of the bolt.