[aguahombre]

 glen, on 2013-February-18, 12:48, said:

So optimal is starting the transfers at XX?

That seems to be true, and seems to be what I see happening...not just with us.

There are some subtleties attached; like 1S (X) XX (P):

1NT accepting the NT contract, or 2 any here by opener, is not only natural, but also a weak opener..lest she would pass. This can result in some plus numbers on defense (or in 1SXX) similar to the traditional purpose of the redouble.

[Free]

 ggwhiz, on 2013-February-17, 12:11, said:

That could work but I prefer to play it off.

Something like 3♣ pre-emptive on ♣QJTxxxx and out can cause havoc opposite my 12 to possible big hand opener.

Yeah, me too, but OP clearly stated 3m was Bergen and was inquiring about 2NT. So if you decided to play Bergen on, you might as well play system on completely.

[jogs]

 TWO4BRIDGE, on 2013-February-17, 12:36, said:

I like the 3C/3D as "fit-jumps" , which leaves 2NT as the Jordan limit raise.

And for the 4 card "mixed raise", Rodwell suggests to use 3M since he says ( paraphrased ) "the 3M-preemptive raise rarely comes up and when it does, is not very effective" .

I think Rodwell nailed it. Why play bergen? The LAW
does not protect overbidding. Don't play 3M as
preemptive. Don't play bergen without comp.
Play 3♣/3♦ as a fit jump with or without competition.
Only without competition it is forcing to game and
suggests at least mild interest in slam.