ARC LS5mkIII: Is it old sound!

I have enjoyed my LS5III for the last three years, longer than I have kept any one piece of equipment. With the advancement of technology from ARC, more specifically the LS25 and LS16, will I be getting a better sounding preamp. More specifically, is the LS5III worth hanging onto or is its time up. Thank you in advance.
I have also used the LS5mkIII for the last several years and I believe that you have to go with a Ref 1 or the new Ref 2 to get better sound. I auditioned the LS25 and found that it was different from the LS5mkIII but not better. The LS25 was more detailed but the LS5 had better bass extension and was warmer sounding especially when listening to jazz. I also auditioned the Ref 1 and think that preamp combines the best qualities of the LS5mkIII and the LS25. The dealer that sold me the LS5mkIII feels the same. I haven't listened to the Ref 2. I decided to keep the LS5mkIII because I didn't feel the LS25 was an improvement and I have not yet found a used Ref 1. The Ref 2 at $10,000 is out of my budget.
There are people who do mods for ARC preamps if you really want to upgrade this is much more economical. can't remember who, sorry, they're in canada somewhere, perhaps there are others as well.
To the recommendation about mods to components, I disagree. On a component like an ARC preamp, with a good reputation, you may or may not be satisfied by the new sound you get after another party modifies your component, but unless that modifier has a good, well-known reputation with that component, you will likely lose money when it is time to sell. And even with factory done upgrades, it's funny how often components are for sale soon after being upgraded. Just like changing components, upgrades are an unknown until you hear the component in your system, and often the changes made make the component no longer match with the sound of the rest of the components used.
i have afriend who had infini caps put in his research didn't do the upgrade,but put together the parts to do the job. they might upgrade it for you. i haven't heard it but,several friends told me the differnce was amazing. richard grey [the richard grey power company] did the upgrade for him.
If you really want great new sound try the Ls15. It will blow the doors right of your 55555555555
Try the conrad johnson premier LS16,i had a arc ls5 mk3 for a few years,until i heard the cj LS16.arc is very good,but the cj is the way to go.