My question is: Is anyone here an experienced presales engineer (current or past) and what, if any, training did you find useful? I'm looking for the surprises here.

I have been in IT for about 20 years now and am transitioning from post-sales consulting/engineering with a focus on virtualization and storage into the pre-sales engineer for an MSP/MSSP/consulting/CSP that partners with all the usual's like Dell, VMware, Microsoft, Cisco, WachGuard, etc. When I say "the" pre-sales engineer, that's what I mean. There have never been dedicated pre-sales engineers in our company before. I will be the first. I've been doing pre-sales engineering in this company for 5 years but only in my area of expertise and our focus was always on the engineering. Now I have to branch out into networking, applications, cloud services, etc. so I can have random conversations with random clients.

I am looking at a lot of the "basic skills" type certifications to expand into new areas and of course the vendor specific partner training. But where is the training that I might not have thought of looking at? I've been a "server infrastructure" engineer for decades and happy with it so this is the first time I am really poking my head out and I have to believe there are things I am not thinking of or huge mistakes I could make in going down certain paths in the wrong order etc.

Thanks in advance.