CDI is the least expensive option and it’s a reliable piece of equipment.
You can’t go wrong with a Schaefer, Harken ESP (For cruising)or Mk4 for racing, Furlex by Selden, Profurl, Hood, Facnor or Alado .
They’re all good brands, and everybody likes the one they know best.
A few Major distinctions:
CDI and Alado have integrated halyards and don’t use an adjustable tension halyard. Pros: They can’t develop undesirable halyard wrap and don’t require any Halyard hardware modifications. Cons: More difficult to change headsails. You can’t adjust luff tension.
Racing furlers have two grooves for headsails swaps. And removable lower drum units. Cruisers rarely care about that.
CDI and Schaefer Snapfurl have plastic extrusions that are very Simplefor the DIY installer. Others have aluminum sections that must be assembled. Schaefer Snapfurl uses the boat’s Genoa halyard, just like most other furlers, but as I wrote previously, CDI does not.
All will last you 10-20 years with minimal maintenance. Flush the bearings top and bottom with fresh water after use.
Furlex (by Selden) comes as a Complete kit with a new forestay with very well written instructions for the competent DIY-er. If your forestay is old, you should consider replacing it at the same time you replace the furler.