I agree with rnvinc and he knows WAY more about the subject than I. Get the largest you can afford. I had a 700 series and was not satisfied with the quality of si for the money and moved up to the 800 and it’s great. Some people love the 700 and it performs fine for them.

The comparison between the 1100 and 800 is not the same as an 800 to a 900. The 1100 has is about 4 inches larger than an 800. The difference between 800 and 900 models is only 1 inch so the difference won’t be so drastic between those two models.