I want to buy the EVE 306 Ah MB30 cells, is there a real advantage to compare the LF280k cell
Yes, there really is, lithium battery manufacturers, have been continually improving the production techniques and tweaking the structure of the chemistry to increase the quality and charge and discharge, along with lifespan.
The MB30 and MB31 are real, they are the next generation of cells from EVE, CATL and others also have next gen cells up to 18000 cycles, but that is in a fully climate controlled container for use on the grid, not for your little battery for your home, but you are almost guaranteed to be sold fake, or rebadged CATL cells, so that is why EVE became so popular. The quality is better at EVE if you buy genuine.
What country are you in? You should look for reputable sellers in your country, if you are price sensitive ask for discount. But for warranty reasons its a no brainer. Plus no hidden costs which are still a bit common with Alibaba. Along with fake A grade cells, they are rampant on Alibaba. They laser the QR codes to appear as genuine, and with new dates and with the fake QR excel spreadsheets.
There are at least 1 wholesalers in china who sell to all the alibaba shops, they are the ones who do the sorting and QR code lasering, Hence why almost all sellers are selling the same product with the same fake EVE data.
I know for a fact the stock is up to 2 years old, been sitting somewhere, or pulled out of service in a high voltage pack. It really rare to get A grade outside EVE themselves, and they have resellers in most countries now.