I don't know of any reason to keep them, unless you just want to listen to them :-) BTW, I got trophies without having to hold onto the blocks. It awards for just finding them!
You don't even need the blocks if you want to listen to them. Clicking on the displayed trophies brings up a menu that allows you to listen to any block you want.
@Lucille Ball- No it's not- I got that the other day in Ix with a DB-4 (and hadn't been trying, either). It just takes a bit of perseverance.
Use 'em for shrine donations. That's what I hold onto 'em for- you got them for free, and you can turn right around and convert them into FP, so why not?
You do have to hold all of some of the sets at the same time to get some of the trophies.
And yea, you can listen to them from the trophy, but if you like listening to them while you're out and about or playing them for people, you might want to keep them.
I think when you've gotten all the trophies, you should get a crabpod so you can listen to them all wherever you go (if you have that item with you) without carrying multiple blocks or being in your house by the trophy case. :)
It'd be nice for them to take the SB-1 from the crab's rotation (or give us all an SB-1 ;) ).
@Dja - the reason you got it is because the SB1 folks are popping the crabs to help now. You might have meant that, but wanted to give you the full picture if you didn't know.
You can still get experience from blocks you haven't listened to in a while (sometimes over to 100xp). So if you keep a couple of the more rare drop blocks and listen to them every once in a while, you get get a nice XP reward. Though this bit isn't worth much at higher levels :P
@Djabriil - That's true. That's even more reason to hold on to some of the more rare ones and only listen to them near level up. That way you can get that extra boost you need :)
Yup, it's definitely a lot easier to make the crab happy now that people with SB-1 have been playing it. I've personally done it 5 times in 4 real life days using just regular blocks that anyone can get because of the people who have been going around making it possible for the rest of us (thank you to whoever has SB-1!). The nice thing about making the crab happy is you get 2,000 currants, 1,200 xp, and a full refill of your mood and energy.
As for the original question, there's not much of a reason to keep the blocks once you get the trophy. They're good for selling and donating. The only blocks I play for the crab are the ones I happen to pick up during that game day, then I sell them when I'm done with them. I would only play them for xp if I was really close to getting to the next level.
Oh, another thing they're good for is using the last bit of energy you have if you want to die of energy loss for the day, if you're going for the dracula badge.