I really enjoyed my time as a Solutions Architect, and wouldn't mind at all doing it again someday. The job of a Solutions Architect, or Sales Engineer, or "Presales" is be the technical person in the sales discussion on the part of the vendor who's trying to sell the technical
$thing. The sales rep's main responsibility is to manage the sales cycle (a separate post entirely) and depending on how technical the product that your company sells, it's possible that knowing how to answer questions or sell the customer the right solution is entirely outside of the sales rep's capability.
This is where the Solutions Architect (SA) comes in.
The job of the SA is to have a very thorough conversation with the prospect about what they're trying to accomplish and why they decided to contact your company. It is your job to
- figure out what exactly the prospect needs from your company to solve their business problem and
- set their expectations for exactly how your solution will solve their problem
The second part is the most fundamental, because 100% of the time the prospect will have an idea of how your product solves their problem, but it will be from their perspective. In order to truly solve their problem they need to understand the mental model of how your company and its product works. This is the SA's real job.
All technologists are human and the products that they produce are therefore imperfect. It is impossible for the human prospect on the other side of the transaction not to view your solution as a magic bullet for their problem (I am doing this myself at this exact moment in my new job negotiating with a vendor). It is your job to bring the prospect down to earth and help them understand exactly what the experience will be when they come on board.