I really like my Tutto for my Janome 6600, which is pretty heavy. My view is that if I'm away from home sewing on a less capable machine, I'd rather be home sewing on my 6600. I used to pack my tote with extras, but now have decided it's not worth adding the extra weight. I pack a bag or tote which can be strapped onto the top of my Tutto for wheeling into the building.
I have had my Tutto for several years. (7, I think), and travel with it at least once per month. Last year a couple of the rubber wheels peeled off, leaving the smaller hard plastic inner wheel. To be fair, it happened when rolling along a cobblestone path in subzero temps...
Ordering replacement wheels was inexpensive and replacing them was simple. I like knowing that replacement parts are available, and that when the rubberized wheel came apart, the inner wheel was still there... I wasn't left in a bind.