Last June (2017) I replaced the Raymarine C series that was original (I assume, 2007) and upgraded almost everything with the Raymarine Axiom system.
Bottom line: seriously way better than my C series stuff. Faster, clearer, more powerful.
Good to note they immediately came out with an Axiom "pro", so the proverb always rings true: Don't buy first generation stuff. I think there's a reason they went to Axiom "pro" within a year. I have Axiom "Amateur"?? Regardless, here are the pros and cons.
Pro's:
Lighthouse 3 software system is really really REALLY fast, and you can get updates for this and all other Raymarine systems via WiFi, sometimes I turn my cell phone into a Hot Spot and load stuff. Navionics latest stuff is actually TOO detailed for my tastes, but you can customize, see below.
Boot up time- everything boots up much much faster than my C series, especially the RADAR (which is wireless to my MFD, only requires power cord, one less wire to snake), it seems like it boots up in about 15 seconds or less and whammo I can see.
AIS- comes with AIS transmitter, you can use the AIS reciever from your VHF if you'd like
Screen Clarity/Brightness- Way way clearer, depth of colors wider and brighter.
Reduncancy- Both my Helm (12") and Aft (9") have GPS and separate transducers. Max366 has a downvision/realvision, and I have 3D transducer on the stern, and their recommended 1000W Airmar (275?) Chirp bronze thru hull in the hole where the old hockey puck used to be.
Easy Installation- good instructions, cables were plenty long, ends of cables have different sizes for different applications so you're not putting any one cable in the wrong receptacle, all the things a weekend warrior like myself needs to not chew up too many weekends.
NEMA 2000- Everything is compatible with NEMA 2000, I'm using my Garmin Autopilot, my iCOM radio, my Yamaha engine data is shown on my helm station, etc.
Customization- It seems every last variable of the screens you choose is customizable. Radar overlay yes or no, grid yes or no, rings yes or no, colors, font sizes for data small medium large xl, which data do you want shown on which screen, which depth do you prefer waterline or under transducer or under keel, on and on and on and on. It's almost too much customization honestly, it gets confusing when you set several screens up and don't carry over the exact same setup you did before (but maybe you want a different set of data in your running chart vs your jigging chart vs your trolling chart???)
WiFi- I've got an old iPad the kids don't use at my main helm station as a repeater from the rear MFD which we always have set to full screen depth. This way I can use the helm MFD for everything else, including a panel where I control my stereo system. I also use my cell phone to remotely control the rear MFD if the crew gets out of hand. (BTW the stereo feature is only compatible with a specific series of Rockford Fosgate equipment)
Cons: My Axiom "amateur" MFD is touch screen ONLY, and I've had occasion where the screen has frozen and shut down for some reason, and won't turn back on no matter how many times you swipe your finger across the glass where the power "slider" is. The new AXIOM Pro series is offered with a unit that has both touchscreen AND buttons, so you can do a hard reset and get back in gear. I have yet to solve this problem with my touch screen only. Looks cool, but I'd like a power BUTTON. Otherwise the touch screen is awesome for zooming in and out (redraws instantaneously fast), rotating, plotting, etc....
The other con is the "bridges" or NEMA 2000 switches that you need to purchase in order to network other non-Raymarine products. You spend $120 for a kit-kat sized cable link with one red light for my Garmin (isn't this all supposed to be NEMA 200 compliant, why do I need a $120 switch?) and Yamaha engine data. It all works great, but you have to buy a converter of some type. Raymarine customer service is very good at helping you pick out the specifics for your product, and taking your money.
I'm still figuring it out and have the regional sales rep engaged for a review of my system in the next week to see what the deal is with my touchscreen power. Maybe I can trade it in for a new MFD with an actual button I can push!
Bottom line: seriously way better than my C series stuff. Faster, clearer, more powerful.
My 0.02c
Good luck!