Being able to use the Living Persona as the Master of a PAN might be usefull in some occasions (mostly, hiding things by lending your Sleaze Attribute to them), but I donīt think itīs a vital ability that TMīs desperately need out of chargen. Despite the Name, being a Master only means that you can lend out your Matrix attribute for defensive tests. For gear protection, you can just buy a good Commlink and use that as your official Master, without worrying that you get a Mark on yourself when someone Marks your stuff - and you can even buff it with Complex Forms! Not being able to get direct connection out or link-lock a target of chargen is/was a much more grave issue.
That being said: I donīt know if I miss something here (After all, there are a lot of open questions surrounding Master-Slave relationships, which might be answered by Kill Code and/or Errata), but isnīt the ability to make your Living Persona a Slave of a PAN, which apparently only kosts 2 Karma, a lot more powerfull? If youīre more of an Attack TM, you could use this to get low on your own Willpower or even Intuition and then slave yourself to Rating 6 Link with a Sleaze dongle to essentially buff your Firewall and (passive) Sleaze? Itīs probably not a good long-term build, but a neat trick for street-level Technos.