LMSC
I guess this a question of whether you want something that is perfect for the job that you do 1% of the time and overkill for the job you do 99% of the time or vice versa.
I personally like the idea of dual boiler but the more I read, the more I think it will be more hassle than it’s worth. In reality someone who makes max two drinks at time(in most instances) doesn’t need a dual boiler, however nice it might be for the occasional guest.
I good workflow might make up a lot of the difference between the two machines for multiple drinks