I also played a little with Mambo and from my point of view it's only the menu management where Mambo is ahead. The rest I like completely better in Xoops.

MultiMenu is a good start, but has only 30% of the Mambo Power in this area.

My 2 cents.

If the core could be set to 5 sections instead of 3 columns only, it would probably please most of us.

Header
3 columns
Footer

All customizable from within XOOPS and it's modules.

You are absolutely free to put your center-left blocks in the top if you want - XOOPS has 5 block areas to be placed wherever you like.

Will perhaps be expanded in 2.1, but only time will tell.

I am all for more flexibility in templating. Don't exactly have suggestion for a great solution. Mambo allows for custom naming more slots which is good but the way you assign components to slots is completely up to you to keep track of and offers no visual representation of the slots that are available. Would be great in XOOPS to have an html wireframe with slots in their relative positions based on the selected template and then a drop down or other in each slot to assign modules to that slot. I've attached screen shots of the way Zope templating has been customized where I work. UI still clunky but a step in the right direction for XOOPS I think.