My old one was a Chicago. Easy enough to grab the saw handle and twist to see how rigid the relationship between the blade and base are.

My Ryobi is fine as long as you don't twist on it while cutting. My Chicago Electric required always pulling in the same direction during cuts to take the slack out. Ideally there should be no flex even under significant pressure.

Learning that lesson the hard way I'd never buy another compound mitre I hadn't gotten my hands on first. Choose stiffness between blade and base over any brand loyalty you may feel.