1) It shouldn't make things harder/less interesting for existing players.
2) It shouldn't be unwelcoming/overwhelming to new players.
A number of other goals could/should be met (make the game more fun/interesting, address mech balance issues, promote voluntary spending on the players part, etc.) but if the above two aren't met then the other issues won't actually matter.
With that in mind let's compare the existing skill tree with the version on PTS2 currently (ST2), to assess the basic impact it will have on new/existing players. Observations/summary will follow the skill comparison.
Existing Tree:
Tier 1 - Basic (listed in the order they might typically be acquired, Elite/X2 values in brackets)
Spoiler
Tier 2 - Elite
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Tier 3 - Mastery
Not covered as it isn't directly replaced in Skill Tree 2 (ST2).
Let's take a fairly typical Mech, the Hunchback 4H. We will duplicate the effects of the existing skill tree and see what that might involve for new/existing players. Given the design of ST2 we can't simply select the same effects/bonuses, we instead unlock a path of nodes which sums up into the desired bonuses.
I will unlock a minimal path, uncovering mostly 'good' bonuses along the way and avoiding useless/unneeded ones.
Tier 1 Basic: Cool Run + Heat Containment - Operations Tree
Spoiler
Tier 1 Basic: Hard Brake / Kinetic Burst - Mobility Tree
Spoiler
Tier 1 Basic: Twist Speed / Twist X / Anchor Turn- Mobility Tree
Spoiler
Tier 2 Elite: Speed Tweak (Mobility Tree) + Quick Ignition (Operations Tree)
Spoiler
Tier 2 Elite: Fast Fire - FirePower Tree, and maxing Cool Run/Heat Containment (Operations)
Spoiler
Issues Raised by Skill Tree 2 (ST2)
Spoiler
Observations
I am interested in the possibilities offered by something like the skill tree. I would be happy to customize my mech to a greater degree and choose abilities which more closely suit my playstyle.
I believe taking an already-difficult and hard to master game like MWO and adding even more complexity/time sink to it would be a backwards step. Particularly increasing the time, XP and C-Bill sinks per mech posed to new players seems unwise. On the other hand, we have the elimination of the 3-mech rule so skilling up a single mech variant will actually be faster, skilling up 2 mechs of the same type about the same, and skilling up 3 or more mechs of the same chassis will be slower and more expensive. Which just makes selling 'mech packs' that much trickier.
I was concerned that it took 61 of my 91 nodes to replicate current basic/elite skills, before counting anything for modules/consumables. Hopefully 30 nodes remaining represents a fair bit of flexibility.
Finally, I spent 57 minutes in the skill tree setting up that one mech. Granted, it was my first one, and I was taking some notes. Even so I suspect ST2 will take significant time away from actually playing matches, with a questionable return on entertainment value (since so much of it is simply replicating what is done now on a single screen with 13 choices and a few clicks).
I like the way ST2 is heading but think it could definitely use some trimming and some new-player-friendly adjustments.