This is just a personal opinion - so please feel free to disagree!
I do not like IS/OS/VR etc. When IS was introduced it was a lifesaver - but then we were dealing with 400 ISO (max?) film. These days is it really useful?
I primarily shoot wildlife with the Canon 800mm F5.6 L IS on both FF and crop bodies. This lens is mounted on a tripod whenever possible but, due to practicalities, it is used hand held about 1/3 of the time. I bought this lens in November 2013 and by December I was getting annoyed at the number of shots lost to IS - but the perceived wisdom was that IS is wonderful?! Anyway in late December 2013 I turned IS off. Haven't used IS since and am much happier with the lens!
On static subjects it didn't make much difference, but the AF lock was significantly quicker with IS off! However my "Keeper Rate" on moving subjects improved markedly to say the least! Even hand held, with the longest lens Canon currently make, I find IS to be more of a hazard than a help. It just mucks up AF too much - as others who have tried "IS OFF" have found.
Certainly IS has it's uses - I just have no idea what they are?
When you decide which lens to buy make your decision on the quality of the lens and not on some feature (IS) that will degrade it's performance..Having said that it is a fact of life that manufacturers insist on fitting this (IS/VR/OS) feature so we have to live with it! But if you want reach and decent quality on a budget then the Canon 55-250 is hard to beat!