The CI4 is really nice, but not sure you are going to get $100 worth of performance out of it over the I. You get two more bearings and a 1 ounce lighter with the CI4. Also the Curado I comes in a lower gear ratio that the Chronarch does not.
If you were looking for one or two reels and wanted to treat yourself, the CI4 is sweet, but if you are looking for a handful of awesome reels that are going to perform great, get the I's