I've tried the Petpod, Catmate 10, Catmate 20, Catmate 50, and Petsafe 5.
Avoid Catmate 50 feeders like the plague: not burgle-proof; absolutely carp mechanical timer that (IIRC) can only dispense meals once every 4 hours and even then can be unreliable for the timings; huge amount of space needed because the cat needs to rotate around a very big feeder.
Catmate 20s are OK in the burgle-proof department but again have a mechanical timer. They can dispense 2 timed feeds. The timer is clunky but you can set it to within +/- 15 minutes of desired feeding time. I did have problems with the clock mechanism (failed to advance the release mechanism and therefore feeder failed to open) but the manufacturers replaced the clock mechanism FOC. There is no cover for the battery compartment and a rambunctious kitty might feasibly knock the feeder hard enough to dislodge the battery itself (and therefore the feeder would not open). On the plus side, the Catmate 20s come with an ice pack and you can set the timer for up to 48 hours: great for a non-diabetic cat where you need to be away on a weekend and need to dispense large feeds but not a great advantage when using the feeders to dispense mini meals for a sugar cat.
Catmate 10 feeders have similar strengths and limitations as the Catmate 20s with the following differences: they can only dispense 1 feed in a 24-hour period; and they don't have space for an ice pack under the feed tray.
Petpods have a digital timer, covered battery compartment and are very reliable in terms of dispensing feeds consistently and at the required time. Downsides are that an amoeba with chronic fatigue issues would have no trouble breaking into them and there is no room for an ice pack under the feed trays.
The Petsafe 5 is burgle-proof, has a digital timer, secured battery compartment, and there's space for an ice pack under the feed tray. Although the feeder is not insubstantial size-wise you do not need much room to use it because it rotates the food toward the cat. The feed tray has (spookily) 5 compartments. One meal is available straight away and the other four are dispensed at the times you set. You can program up to 9 different feed times which means that you can serve timed feeds right throughout the day without needing to reprogram the unit for daytime and nighttime feeds; you just need to reload the feeder tray. The other advantage of the Petsafe 5 is that it will rotate unfinished meals back under the cover so that you'll know how much your kitty is eating in the intervals between feeds. Also, if you ensure that the timer is set to rotate 2 hours before preshot is due then you can ensure that preshot tests aren't food-influenced (subject to the first meal in a 5-meal cycle having been finished, or else leaving the last compartment in the cycle empty). The only limitation with the Petsafe 5 is that it can only be programmed to dispense meals over a 24-hour period. (CAUTION: It's vitally important to make sure the feed tray is properly seated when you set it into the timer. If you don't seat it properly the tray won't rotate to the correct position under the access opening in the lid, leaving the cat unable to get at the grub.)
Mogs
04.04.16 - EDITED TO ADD:
A Previously Unidentified Plus for Catmate C10/C20 Feeders
Since Saoirse had her eye op recently she has experienced facial soreness and consequently has not been able to feed comfortably from the Petsafe 5 because the compartments are relatively narrow and deep compared to some other feeders.
In this instance I have reverted to using Saoirse's Catmate C20 feeders again. The feeder trays are shallower and wider and in her current sensitive state it has been less uncomfortable and therefore easier to eat from them. (Something to consider for cats who have mouth/facial sensitivity.)
All that said, provided we can solve Saoirse's sensitivity issues I look forward to going back to using the Petsafe 5 but, in this particular instance, I've been very glad to have the Catmate C20s to fall back on.
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