Hello; Do not have experience with the filters and heater named.
On a bigger tank I liked to have two heaters in use so that there is less chance of total heating loss in the event of a failure. Some of my heaters had very short durations of proper function. The ones that have survived, by default, must be good ones. I will at some point look at the brand of these die hards and post the makes.
I have only used the type that hang on the rim of a tank. I learned to look for some sort of proper sealing at the top to keep moisture out. Water can find it's way inside the tubes. I have seen them continue to function (for a while) with an half an inch of water inside the tube and touching the heating coils.
I also look at the type of fittings and components inside the tube, in particular the adjustment screw and the contact points. Finer threads on the adjustment screw seems to be better and allow for more accurate adjustment. I also like a material for the adjustment screw such as brass or stainless. I can not always tell the better quality stuff by looking, but the poor quality stuff becomes more oblivious after throwing a bunch in the trash.
I acquired a submergible heater with a used tank last summer but have not used it yet. I suppose there is a way to adjust the temperature, but do you have to remove them from the water? I find that I have to change the heater settings as the seasons change.
One other thought. I do not care for too much wattage in a single heater. Thermostats have and do stick. A powerful heater can cook a tank. For me if 200 watts is needed, I will often use two 100 watt heaters. I will pull one in the warmer months. I also check the adjustments more often in the spring and late fall. That said, I do however have single heaters that have proven trustworthy, in tanks.
I tend to run a little less wattage than absolutely necessary for the coldest time of year with a few spares handy to add if needed.