Hey Steve,
multiple newsletter formats to choose from could be great - and if you give the option not only to choose the format but also which block of content should be included /* with the only mandatory block of ads - you have to live on something 😉 */ it would be awesome!
But have you thought about a poll where you give the community a list of possible options and so you will get know us better...
because at the moment I would think, most of feedback you receive is asks for change or a globally thank you. The content seldom write letters ^^
//Sarus