Yes, I admit I've been promoting dollars-per-mag mantra recently to create some extra attention (GPU mining always being the hottest topic in crypto, pun intended) and to point out that older GPUs are not necessarily weaker when running BOINC. But there are many scientific algorithms which will never be ported to GPU and this low power approach of yours is the future really, although it may not win many upvotes in "show your powerful rigs" threads :)