I can accept CA at certain levels or price points. I pretty much accept it at scopes under $2k but above $2k I expect CA to be controlled better. Sometimes CA can be exacerbated by poorly configured diopter, other times it is simply the scope itself but I’ve even seen manufacturers “fix” scopes where customers complained enough and they got back a scope that controlled CA better. Every optical system has CA but engineers will control it through the optical formula which might include the use of certain glass. Fluorite exhibits qualities that improve resolution and help to control CA but fluorite is very expensive, and popular among newer optics today is Japanese “Super ED” which has many qualities similar to fluorite at a cheaper cost, for a little more info check out this article:
https://marchscopes.com/news/1644/
Keep in mind not all glass is the same so while some manufacturers use the term “Super ED”, ED or HD it doesn’t automatically mean the scope is going to compete with a Tangent Theta at an optical level. I am reminded of a few years ago when the term “HD” caught hold of the bino world and everyone and there grandmother started using HD in their marketing and model numbers, but clearly not all HD is equal. The new craze is ED, but compare the Vanguard Endeavor ED at $300 to the Swarovski EL at $3000 and while both use “ED” glass the IQ is very different.
So while the DMR II and XRS II both share what Bushnell is calling ED Prime glass and claiming to reduce CA (which has been corroborated by many owners) we aren’t certain if it’s the same as other manufacturers ED labeled glass. Besides, glass alone doesn’t remove CA but other factors such as the alignment of the glass in the tube also plays a role.
In a day and age where machines are making many mass produced scopes and lack of good QC I can see how some scopes will slip through the cracks and may exhibit worse CA than the typical scope from the model range.
That may have happened with the Mark 5 I had, but I’ve also seen heavy CA in the old Kahles K624i and the worst I’ve seen came from the early Steiner T5Xi scopes which I’ve heard Steiner has done a much better job with in later generations.
All this to say that just because you had a DMR II that had horrible CA, and I had a Mark 5 that had bad CA doesn’t necessarily mean that all the scopes from that model line will exhibit the same.