As far as I know, there hasn't been a run of FiiO portable DAC/amps on Massdrop recently. FiiO has been known for their solid quality and fair pricing across the majority of their product lines, making them useful to take on the go and also to use equally well at home with a computer or on the go with a DAP or fancy phone. Headfonia has a crop of reviews for the product line with some comparisons (particularly for the E17 Alpen 1 vs. the E7) for further reading.