I unlocked an E10 with Omnius... This is what I can say:
For unlocking, it works easy and clean, includes all your drivers, you just need basic widows "driver installing" knowledge.
It's the cheapest one I found for 1 phone unlock.
In theory, Omnius unlocking is a permanent solution for SIM unlocking...
In practice: Currently you can't unlock the bootloader of an Omnius SIM-unlocked phone. So if you are interested in modding, don't use Omnius today. Use unlocking codes instead, multiunlock or setool2.
davinci is cheaper than omnius, but also lacks bootoloader unlock also.