I love them. and yes I originaly thought they felt heavy but I found nothing is lost in performance and they stand out in stronger winds when my fire wire can get blown around a bit. The build quality is excellent and the bamboo really nice and more importantly they ride really well. The board you choose depends on the conditions you ride. All my friends who tried them now want one. As a caveat we are not experts - far from it, but I have riden quite a few boards.
What type and size of waves are you going to be surfing? The Maquina is a smaller board for use with more powerful waves , the Salerosa is a more efficient board for use on less powerful waves, also better for you if it is your first surfboard as it is more stable. The Maquina with its squash tail has a more responsive and aggressive turn.
If are looking for bamboo laminated boards for the toughness, take a look at the Liquid Force range, they are seriously strong and the 5'10'' is amazing!
The maquina is the more polyvalent one, to be used in all conditions (side or onshore). Perfect balance between easiness, reactivity and speed. But don't hesitate to repalce the fin's by smaller ones if you're under 75kgs. The chiatta is also a very good board for lightwind and mushy conditions. Very confortable.
The weight is a little bit above the average surfboard weight from others brands, but it reflects the top build quality. Both of them also exist in "pro" version: no carbon, different pads and straps, lighter weight.
Have a look here if you want to see both of them (maquina and Chiatta K-pro), in a "non-pro" waverider feet (small wave light wind session with religion 10m²) !!