if have to restrain myself then lap band doesn't work?

I had a band, and as an explanation would say that they can be temperamental. The level of restriction from the same amount of fill will feel different for different people (my DH has a band too), and varies with the time of day, your state of health, the temperature of what you're eating, and the type of food you're eating. Sadly, the foods which I found easiest to get down were ones which were bad for me - chocolate, chips, cookies etc, but not salad, fruit or protein, which would get stuck more often. Because of this bandsters have to use willpower - I would say its 30% the band and 70% you.

I haven't had RNY, but part of the DS is a sleeve gastrectomy, so I have something to compare with. Sleeve is more constant that the band, restriction stays the same, and you don't feel as hungry - you aren't producing ghrelin, the hunger hormone. I'm only guessing, but if you have sleeve alone or RNY to restrict your capacity, you are perhaps up to 50% the surgery and 50% you.

I had DS as revision, which also involves rewiring your insides. As a result I can eat fat without taking in the calories (so don't have to restrict fats), have to eat as much protein as I can and don't fully absorb carbs. Carbs also give most people gas, which puts you off eating them. I would say the DS is 90% the surgery and 10% you - I need this, as I suck at dieting.

Despite all this though you need to talk to a good revision surgeon about your options - one who does all the surgeries. You might choose to have your RNY altered, or have it reversed and have something else. But what choices you have will depend on whats happened with your insides in the meantime.

Sal
 

The lapband is only restrictive(VSG too).  RNY & DS have a malabsorptive component.  Depending on the amount of your original bypass (usually proximal) adding a restrictive device may not be what you really need.  Since you have a RNY already you should really speak to a doc that specializes in revision of RNY.
Have you had an EGD to see what  your stoma and pouch look like now?  Since you are 12 years out its a good bet your pouch is larger than it was when you had surgery.  That said you might do best by extending your bypass rather than having a band over it.  The shorter your common channel the better the sustained weight loss.  A revision to DS could be an option, far more riskier than just shortening your common channel since your pouch would need to be taken down and made into a sleeve.  Either way the shorter common channel means you will reqire more protein and supplements since you will not absorb much of what you eat. 
Every option has its good and bad points, you just need to figure out which will work with you and your lifestyle.
My spouse and I have lapbands and are pleased with it. 
Good Luck

After 2 1/2 years with the band, I had to have mine removed last month because of constant reflux and only being able to get liquids down.  That was with my band having been emptied.
I had a revision to RNY last Monday.  I lost weight with the band but then my band stopped working for me and my health!

 I had RNY Proximal in 2001.  Lost a great deal at first.  Got down to where I wanted to be and gained some of it back.  I am choosing to go to the ERNY.  I am scheduled for next Friday.  This is where they make the common channel like the DS but leave the pouch alone.  Like Paperboy mentioned, taking down the pouch can be more riskier.  And the long term benefits you get are from the shorter common channel.  There are many types of revisions to choose from.  Choose what best suits your needs and your life style.  Good luck to you.  I hope things start looking up for you.