Well, Since Jeff gave me some nice props here's my two cents. I manage a store that sells both Caldera and Dimension One Spas. They are both High Quality spas made by two of the industries leaders in: Qulaity, Dealer Support, Customer Service, Design and innovation. Having said all of that here is a comparrison breakdown of the two brands.
Caldera:
Ergonomic seating with a "No Float" Design
Laing Fast Flo Heater made out of Incoloy (5yr unconditional warranty.
Foot Ridge: helps to prevent floating
Powerful jets that are completely adjustable to allow for a wide range of hydrotherapy options
Each seat works a different part of the body
Spa Glo interior/exterior lighting standard on all aquatic melodies and Utopia series spas.
24 hr filtration and ozonation
CD Ozonator
Dimension One:
Ergonomically designed seating to prevent floating
Interchangable and adjustable jets allow for limitless combinations of hydrotherapy. All jets are flow adjustable at the jet face.
Ultra-Pure water mgmt system: provides 24 hr filtration and ozonation, has two contact chambers that eliminates potentially harmful offgasing produced by ozone.
Digital message center: provides self diagnostics of spa, tells you when to drain your spa, clean your filters, change your vision cartridge, automatically shuts off heater and circ pump when water level is too low, tells you if you need service if a problem occurs.
Neck Flex Jet System: Patented height adjustable pillow provides hydrotherapy to your neck, reguardless of your height.
Dynamic Massage Sequencer: Available on select models. Makes the ultra-lounge into a masseuse that has cascading massage. Have your D-1 Dealer show you how this feature works (difficult to put into words properly).
Any questions please let me Know.
Jason,
Store manager for a D-1 and Caldera Dealer
