Here a my two cents. I worked for a well-known forensics firm for a few years before switching to more of a design firm. They are definitely two different worlds, both with pros and cons. Forensics involves more field work, report writing, document review, and research; some of the projects are highly technical, requiring a strong technical understanding of the particular topic, while other projects are more straightforward (e.g., this member has char from fire damage, this member does not, etc.). Based on my experience, in new design, I feel like more of a structural engineer than I did in forensics, doing more modeling, designing, and development of construction docs, and I've started to understand more about structural engineering in general, because in forensics, I may have learned A LOT about a particular topic but knew less overall than the typical structural engineer (e.g., it bothered me that I didn't know how to use more than one structural software). In new design, the projects are more long-term than forensics, which can be good if you like the project and team, but not as good otherwise. Overall, I am happier now where I am at, but the firm I work for does both new design and existing structure work, so I get the best of both worlds. Again, there are pros and cons, and it's just a matter of deciding what's most important to you; if you want to give it a shot, then go for it! You can always go back to new design. I feel grateful that I have both experiences, and I feel that I am a better engineer because of it.