There are only a few third party external focusers that have tilt adjustment. You can count them on one hand with fingers to spare. Tilt can be a problem for all cassegrains, not just GSO's, and Newts too. Sometimes it is not focuser tilt that is the source of the fix. Sometimes is the position of the rear cell in the tube that's all that needs adjusting to achieve exactly the same thing - the rear cell may not be sitting totally hard up all around the tube for example.
Then load the focuser up with a camera and associated stuff, and not only is the focuser challenged, but the structural integrity of the OTA is also due to flex. The design of the rear cell of a Cassegrain is vitally important for this reason, as much as the tube of a Newt. Carbon fiber tubes need very careful care to avoid flex (but that's a different topic).
All Cassegrains and Newts will need tweaking when you get them and every now and then, unless you are very bloody lucky. What most compromises the collmation process is the design and build of a scope. Poor choice of materials, components and fabrication will lead to major frustration. HOWEVER, it is good to know what the challenges are so when faced with a difficulty (regardless of what scope you have), it will help you nut out what needs tweaking - be it just collimation or a material aspect of your scope. And if there is mirror shift when focusing, you need to do ALL your collimation and focusing ONLY IN ONE direction in the turning of the focuser. With mirror shift, you CANNOT achieve collimation both inside and outside of focus. You need to work with your scope, not against it
Just don't jump to conclusions before you either dismiss buying something or chucking a dummy spit in frustration and pinging the scope over the fence... What spending $$$$$ will do is reduce the number of potential problems, but won't eliminate them all. I still struggle with collimation sometimes, and it means I need to take a step back for a break or ask someone as I may have missed something as frustration won't let you see past your nose.