Been playing NW since SC2 was released. It's fantastic replay value, worthy of purchase if that ever becomes an option.
Though balances and strategies seem to go through phases, I have noticed in the last 3-6 months that the weakness of new players is increasingly becoming a huge lopsided-factor in team victory. I haven't had a >40 minute game in ages.
This isn't a simple case of "better players will win more", because that statement does not take into account the team dynamic.
Let me offer a combined hypothesis, which is of course open to others' criticism / rebuttal:
*1 - Nexus Wars has significantly lost noob-friendliness.
*2 - So, skilled players are frantically moving away from pub to pre-formed teams.
*3 - Thus, pre-formed teams are crushing the random pub teams, driving away new-to-middle level experienced players, and causing a skill vacuum.
NW has always been about countering, which is the core gameplay. I don't know if any one re-balance or change would restore what I feel to be lost in terms of new-player-approachability. Move from two-lanes to one lane? (This was an awesome idea I'd like explored again). Substantially reduce the unit cap? (25-30% reduction would lessen unrecoverable pushes that require double nukes.)