It will be interesting to try it out.
The functionality of the Raspberry Pi as NAS inside your LAN will be severely compromised by the rather slow ethernet connection (max 100 megabits). This translates in real life to a throughput of not much more than 5-6 megabytes/second. My Tonidoplug2 has a throughput of up to 20 megabytes/second. However with "dwindling stocks of Tonidoplug2" (and no Tonidoplug3 on the horizon) Tonido on the Raspberry Pi might be a nice alternative to try out.
Where can we download the software?