I think all the ones youre looking into are going to make you happy. The difference is things like customer service and warranty and depending on where you are, domestic vs international. If youre in the US and something needs to ever be repaired or replaced shipping costs come into play. Another factor, many Modders constantly update, or discontinue parts so that adds another what if.
Regarding the Polidiac vs ELA , I hear both are amazing in the conductivity area, difference is Poldiac is sterling silver and ELA has Gold and Rhodium. Silver has amazing conductivity but tarnishes, rhodium does not. With ELA you can take everything apart and either wipe with a cloth or rinse with mild soap and water and its clean. No need for abrasives or polishes etc.
The Roller I hear good things about, but not real sure about the details. I think you are probably going to get the best for your money with the Poldiac or ELA if you just think investment, you wont lose your money, if anything it will retain the original price or better. So it comes down to whether you like high ( not really high, but more) maintenance or easy with ELA.
Polidac will need more care, cleaning and more prone to surface scuffs; high fashion runway model
ELA is built like tank, very scuff resistant, lifetime warranty ; US Marine...... forever
BOth are beauties.
