In my opinion you should play what you enjoy.. SnGs are fun... You''ll even find me playing the odd MTT (but only on a free roll!)..Ultimately a good ring player can play more tables at one time and choose his tables and he has more choice of tables - so over time the greater +EV play is Ring.
I find Ring more exciting because with six tables it's rare to go five minutes without action. Also, betting out a marginal hand on Ring I find a lot more exciting because in order to maximise return from top pair/marginal kicker against a draw.. you have to play it close to the wind. I can also get 'into' ppl.. Over thirty hands I have usually got someones play down (ok sometimes I'm wrong).. but then exploiting that play brings out the sadist in me

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Mathmatically Ring is a complete challenge. Some tables can't be beaten however good you are, others can be beaten well - but not controlled, others can be controlled but not beaten well.. I find the way tables flip between these states very interesting. There is also the 'just joined the table effect' - and the effect of a sequence of good hands.. and that's before you take into account the other players! ..the list is endless
Ring NL is hard to play well. A good starting point is to read all the books and then work out 'your' game which exploits all the ideas/weaknesses in these books - so even the majority of strong players won't have good weapons to use against you and responses other than 'fold' to your plays will get them into trouble. I ended up with 'my' game after a load of maths and analysis.. My hole card selection and preflop betting is very odd in many peoples terms but it works for me. Get your winning game then modify/play around with it..Some of my biggest wins/plays in NL poker have started out as massive financial losses
For me the big breakthrough in Ring was to realise that I must come close to losing every hand before I maximise returns. e.g when I go all-in with AA preflop I want as many callers as possible - even though I know that the odds shorten for every additional all in.
The second big step was realising that in ring you play your hole cards in the context of how you've played your last 20 hole cards. (i.e maximise your table image). Looking at individual hole cards/flops plays tells you about odds etc but you should also assess how the table sees you. As a crude example.
1] You get AA - you've folded 18 of the last 20 hands - you go all in. Everyone folds
2] Same table: You get AA - you've had a run where you've had good cards but no-one has seen you to showdown. You may well get a caller because ppl think you're bluffing.
How do you dictate your table image and maximise opportunity? Answer this and you'll hit 10 BB/100 on 0.25/0.5
Must say the bonuses are nice too...
Bob