So if you had a pair of Atman, what would you want?
Also, take into consideration this useful data from BGG:
All Listed Ice Mean: 3.05 Median: 3 Mode: 4
All Listed Ice With ETR Sub Mean: 3.31 Median: 3 Mode: 3
Based on that, and all else being equal, the best value for Atman
appears to be at 3 counters, with 4 a close second (Ichi 1.0 is
effectively ETR with programs out).
First an analysis at each strength point:
0: Breaks Chimera and Rototurret and only 1 Datasucker counter for Ice Wall.
2: You'd be flexible enough to both not miss Enigma/Datamine while being able to reach for 3-4 str ice, but you'd need to spend 1 Datasucker counter every time you broke a fairly common 3 str.
3: Breaks Wall of Static/Neural Katana/Caduceus/Viktor 1.0 and breaks 4 str ice with using only 1 Datasucker. However, 4 str ice are very common, so you'd be using those virus counters up quickly.
4: Breaks Chum/Ichi 1.0/Eli 1.0/Viper/Data Raven/Bastion which are all really common and strong ice. Unfortunately, you miss all the 3 str ice, but at least you're only 1 Datasucker counter away from Tollbooth and 2 away from Archer.
5: Breaks Tollbooth, 1 Datasucker counter for Archer, and 2+ for Hadrian's Wall. More easily takes care of the big ice, but unfortunately doesn't have much uses beyond that.
Now an analysis of each pair:
0/3: Flexibly breaks 0-2 str ice and 3-6 str ice, but will use up a ton of Datasucker counters.
2/4: Breaks a good range of ice, but considering the frequency of 3 str ice, will be frequently using 1 Datasucker counter. Also, needs something else to deal with 0-1 str ice.
3/4: May seem redundant since these two are only 1 str apart, but the pair breaks the most frequently occurring ice strengths. That should then save you the Datasucker counters to deal with 5+ str ice. However, needs something to deal with 0-2 str ice.
3/5: Breaks a good range of strong ice, but considering the frequency of 4 str ice, will have to frequently use 1 Datasucker counter. Also, needs something to deal with 0-2 str ice.
Right now I'm leaning toward the more efficient but less flexible 3/4 pair with Crypsis to deal with smaller ice. The pair is efficient because it natively breaks the most commonly occurring ice (saving Datasucker counters for the infrequent large ice). For the small ice, a sort of alternative to Crypsis would be using Personal Workshop/Clone Chip/Self-Modifying Code to play a Parasite midrun and destroy 0-2 str ice (supplemented by Datasucker counters).
(*i*) If you only planned on installing one, how much str would you put on Atman?
(*ii*) If you planned on installing a second Atman, how much str would you put on your first Atman?
(*iii*) How much str would you want on a pair of Atman? (and if you don't have one at 0 str, how would you deal with ice like Rototurret?)