I have two very happy boys who are enjoying their first tall cat tree...  Xander is 16 lbs and Jaxon is 12 lbs (to give you an idea of how they each fit).  It took me months and months to find the right tree for them because they are crazy, active and STRONG Bengals... I've been so afraid of them leaping off the top and watching it wobble and crashing to the floor (wouldn't make my downstairs neighbor very happy, I'm sure!!).  But this is a solid, heavy unit - it doesn't even rock a little bit no matter what these two do. :) I'm so happy I decided to go with this model....  Also, the only thing you need to do to "put it together", is screw the top perch/beam piece onto the 2nd level - that's it!  No tools needed at all.  The only minor critiques I have are: 1) carpeting could be a little better quality, and 2) carpet the underneath of the 2nd & 3rd level perches.  Other than that, I'm (we) very happy with the purchase!!