If you want to optimize I'd say you need high decking pools and then I suggest to be awakened. An adept decker can start with 3 additional skill points in computer/hacking and get +2 bonus for computers from a mentor spirit. This is +5 computers, +3 hacking. Also, you can take the higher concentration power to negate negative dice pool penalties (e.g. running silent) at the expense of action economy.
Now, while you can have ware - if you are awakened money tends to be expensive so if you do mystic adept, you can use increase attribute spells to steal +4 dice for your decking needs. So a net of +9! dice to computer and +7 for hacking just for having a dash of magic. Even with a cheap deck - your limits may be a bit too low for your skill level but you reliably reach these limits. Also if you focus on hacking rather than cybercombat then smoke and mirror means you can get away with cheap decks.
I agree that device level 2 is enough - but I'd rather have an erika and incredible dice pools (and constantly hit my limit of 5 or 6) then have an expensive deck with less dice.
So this is just for being the best decker you can be - I played an adept (not mystic) decker that way and had really good starting dicepools - if I wanted to optimize her more I'd fix her access to increase attribute spells. It seemed for me that being an adept (even if I only had magic 3) gave me far more then selecting the right qualities did. (and being a plain adept you'll have karma for over clocker and the other goodies).