Cleaning these brewers isn't really any harder than any other vacuum brewers. That said, cleanup isn't necessarily a breeze.
The Cafetino brewer is easier for me to clean than the Royal, mainly because I can fit my big mitts into the brewing glass of the Cafetino; I can't with the narrower glass of the Royal brewer. It takes about 5 minutes or less to clean the brewers, and I use the following steps. The copper on the Royal models is also much more susceptible to scratching and oil and water spots than the stainless steel of the Cafetino.
First, I scrape out the grounds from the glass brewers using a chopstick - you could just rinse these down the sink, but I prefer to put them in the garbage or in the compost. Then I give it a quick rinse to remove the remaining grounds. A bit of dishwashing soap and a sponge followed by another rinse, and a few seconds later the brewing glass is clean.
I clean the siphon filters next by first running water on them to remove most of the coffee grounds, then running a soapy sponge on them. I also force water from the running tap through the tube to flush it out. Finally, I'll run some directed water through the filter portion to dislodge any errant grounds. A final rinse and the siphon is is clean. The Cafetino siphon is brass with a palladium coating, and the Royal is gold plated (!!!), but I wouldn't recommend using any commercial gold cleaners, as they coat the metal as part of the cleaning process. A simple wipedown should be fine.
Next come the kettles. The Cafetino kettle is easy - I rinse it well (with the kettle's spigot open to flush it out), then I add a weak soapy water solution to it and shake it like crazy. Further flushing and rinsing and it's done. The manufacturer says that just a water rinse should suffice, but I like to go that extra bit. Keep in mind, any soap residue absolutely kills the taste qualities of coffee, so you must rinse it extremely well, or may just go with a water rinse to clean the devices.
The Royal kettle needs to be handled with kid gloves. Copper is a very soft metal and is prone to scratching, even from supposedly "no scratch" scour pads (my sample shows some results of this while using a soft sponge and scour pad from 3M). It also tarnishes easily and gets seemingly "permanent" water marks (don't worry, they aren't) and fingerprints that won't come out with soap and a soft wash cloth. I'll detail how to remove these blemishes below in maintenance, but you can easily avoid them by just handling the device at its edges, not heating it while it is wet, and immediately wiping dry any drops of liquid.
I do clean the Royal kettle more or less the same way I do the Cafetino, except I use a soft wash cloth instead of a sponge. As long as the inside is clean, I'm happy.
The Royal is definitely more maintenance intensive than the Cafetino is, but that's the price you pay for copper and gorgeous looks.
When cleaning the Cafetino, which is stainless steel, I use a weak solution of OxiClean (the stuff you see in informercials) - about 1 teaspoon for a litre of water - and let it sit for a while. This eats up all the built up nasties, but doesn't hurt the steel inside the Cafetino. A complete flush of lots of water and it's like new.
Do not use OxiClean when cleaning the Royal models, which are lined with Tin. Big thanks to Carl (Fookoo is his member name) for forwarding the following info to me:
Tin is reactive to tri-sodium phosphate, meta-silicate and chlorine. Avoid using detergents or cleansers containing high quantities of these materials.
Sodium phosphate is the key ingredient in Oxiclean. To clean the inside of the Royal thoroughly, all you really need is water - tin is inert when it comes to acidic foods, and coffee stains are not a concern. Just flush well with water, and you're good to go.
For the outside of the Cafetino, I use a product called Peek (website) in the tube which does wonders on all metals, including stainless steel and copper (most polishes can do either steel or copper, or gold, or aluminum etc, but not all - Peek does). I make sure not to get any of this polish on any parts that touch liquids, like the top of the kettle or the spigot. It gets it shiny new and adds a light protective coating.
For the copper portions of the Royal, I also use Peek which has the added bonus of including a protective coating that prevents tarnishing. It works, except on the parts of the kettle directly exposed to flames. The Royal can get pretty scuffed up, complete with seemingly permanent water spots and skin oils (fingerprints) that won't come off no matter how much scrubbing you do with a cloth and soap. Using a polish cleaner like Peek (or Brasso) will remove these marks and make your kettle look like new, except for one thing - scratches are more or less permanent. The caveat here is, don't use ANY abrasive near copper - you'll mar the finish.
Other than these minor concerns, maintenance of these brewers is a non issue. The wood bases have a nice coating that seals them, and the products are rock solid. The glass used in these devices is handblown, heat resistant and high quality, but definitely breakable if you bang it around, especially when they are hot. Use common sense and these devices will last you a lifetime.
Coffee4You offers replacement parts for their brewers, including brewing glass and burners. These are shipped from Coffee4You's San Francisco warehouse. Other parts may be available, including a custom lid for the Cafetino, crystal glass brewer portions for the Royal, and more, but as they ship from Belgium and are in very limited supply, the cost is prohibitive and not recommended.