This is very similar to my own holding. Although I have replaced SPK with STU.
STU is paying a very good return, and although they are facing a legal challenge I do not believe it will impact their earnings greatly.
SPK are facing a huge upset in the near future as Electricity retailers start installing fibre directly to customers and offering high speed internet packages bundled in with their power supply. Trustpower are already doing this and Contact is well on the way, but only in some areas at present.