"Looks like Unreal IRCD became InspIRCd."
No, Unreal IRCD is based mostly on DALnet's old archaic "Dream Forge" software, Inspircd is written from scratch in C++. Inspircd looks a lot like Unreal IRCd because Unreal IRCd is the widely used IRCd and imitation is still the highest form of flattery.
That said, Unrealircd or Inspircd are both "full of features". However, development as all but stopped on Inspircd and Unreal IRCd is still based on old archaic code.
ShadowIRCd, Charybdis and Nefarious are good modern solutions. Atheme services will run on all of them and is the latest "bees knees" software package as it rivals Anope (currently most popular services package.)
IRC Services comparison/History:
Hope that helps