using swap everything feels faster, give it a try, and don't care about the card life, I'm using swap in the same sd card since January and still works like the first day, and in the case you break it (I've never seen that case because of the use) sd cards are nowadays pretty cheap...

I can notice the improvements of swap memory when browsing, reading big pdfs or having more than 2 apps opened, the N800 has not enough ram...