I have had a stand alone tub tub for many years that I use quite often and have tried all of the methods above. Here is my feedback on them:
A. Bromine is definitely the easiest and most stable. The downsides are the odor and a tendency for the water to get foamy pretty quickly. I use my tub almost daily and with bromine I can stretch out the "empty & refills" to three months. That's pretty good for a small tub with high volume use. No real scumlines with bromine and as long as the bromine stays pretty level, all the other chem levels seem to stay pretty level.
B. Chlorine. Make the water feel real nice, smells great, super clear, no bubbles. But it is almost impossible to maintain a safe sanitization level. Especially using bleach. I tinkered with a bunch of different methods, adding stabilizer, trying pucks, straight bleach, etc. with no consistent success. The scary part is that the water would always look incredible, even when it wasn't really safe. I would have to remember to add a splash of bleach prior to every usage. After forgetting a few times and getting "hot tub itch" a few times I bailed on Chlorine.
C. Baqu. I used this for about a year. Isn't too bad when you first start it up. Water is fine, smells OK. But it goes south too fast. You have to have like 4-6 different chemicals and always seem to need to replace at least one of them and they are not cheap. The water develops a scum line pretty quickly and at least for me required frequent empty and refills. A pointless sanitizer.
In regards to filters, I would recommend keeping two filters at all times and rotating them. Clean one and leave it out in the elements while the other is in use. The sun and weather are a great filter cleaner. Every few years throw them both away and buy two new ones.
As an aside, I am so impressed with the Liquidator that I am using on my pool that I am considering getting another and hooking it up to the hot tub and giving bleach another shot. If I could automate the bleach delivery, that would solve my major issue with bleach.