Thanks KLD and brokeda. I looked at IPtomy but it was another brand where pricing information is unavailable publicly. I know what they're trying to do for their reseller network but in this day and age it just drives me crazy.
KT-TD50G seems nice and quite close to the DSX-40. Thanks for the specific feedback on their cordless, you're right, I'd be pissed off to pay $200+ for a cordless phone with no call log! We do have a pool so I can relate to your use case
Now I need to sort out whether I like more the products from brands that come from the VOIP world (a la Jazinga) or hybrid systems such as those discussed in this thread (with roots in the key phone system world if I'm getting the genealogy right). Seems they're merging in terms of feature set, but the devil is in the details.