there are so many groups and so many opinions haha.. but thank you, yeah, I know that it's "easy" when you have all the documents prepared. For me it's more about the fact that you have to leave the country without knowing if or when you can come back, as the process varies from country to country.
so you mean the thai embassy in London? not sure but that seems quite risky. others told me that you still have to choose the embassy from the country you are returning to Thailand from.
What I find the most "exhausting" is the fact, that you need to leave Thailand for the application without even knowing if the DTV will be approved in the end. I heard of ppl being rejected even though they had all their documents prepared. But yeah... an agent makes sense then.