Hi Agros,
If the card you are using now is okay maybe you should stay with it.
I know that when I queried about sound card vs on-board on this forum the general consensus was to use the on-board one as I did not need it for high end use.
I take it you have updated all drivers/firmware on your sound card?
If you really wish to update this card I would make a 'cheat sheet' my terminology, basically it's your computer system plus peripheral's, IE; OS,CPU, GPU, etc, speakers plus anything else that may be attached, any games, music played, (Jazz,R&B,Pop,Classical,). All typed out on a sheet of paper that you take with you to the shop.
Helps the salesman to fully understand your system. Try & get a salesman that has some computer knowledge, not a "cash collector/bag filler".
Let them know your needs, plus budget limits & hopefully he/she will put you on the right track.
Also find out if you can exchange/refund the item if it does not come up to your expectations, as in my case I purchased an electric razor 3 disc type but all it did was rip out my hair, so I exchanged it for a foil type & have been happy since.
The last thing you want to do is spend good money on a card only to find out that there is no difference from your last card.
From what I can see your card was mostly designed for music & not games.
The "Platinum" seems pretty good, just one comment regarding headphones, while music plays through them just fine, it only lowers the volume of the speakers instead of muting it. The control panel includes an option to mute speakers when headphones are detected, but it mutes the speakers until headphones are connected – and when they are, the speakers and headphones play simultaneously.
But if you don't use headphones then you have no problems.
Ben.