Every bottom-projection printer (Form 1, Titan 1, Pegasus Touch and iBox Nano) needs the resin tank changed regularly, the constant peeling of the tank from the part will erode the tank over time, making it cloudy. Top-projection printers (LumiFold, LumiPocket, Peachy) don't have the same interaction between the resin and the tank. You can keep the same tank on a top-projection printer for as long as you can stand to look at it, depending on the conditions and materials, the sides of the tank might get a slight resin film on them that looks kinda grungy but it won't affect printing at all. Also, top-down printers can use a standard PVC bucket for the resin tank if you want to, so if you do want to replace it, it's not expensive.

That said, bottom-projection printers are generally higher resolution than top-projection ones, tend to be smaller and much more resistant to vibration around them, making them much better suited to an office environment.