2+ gives much more torque in the mid range and is safe providing it is set up and logged properly. On the other hand, people have said 2+ is a step too far and problems will develop over time.
Me, i went stg 1, stg 1+ (bdm cai with stg 1 map) and then straight to stg 2+. No problems so far accept a boost leak but plugs, filters, brakes etc all have to be changed more often so bear that in mind.
I say go 2+ and then you can scale it back to 2 quite easily if/when you want to.