64 vs 32 bit - state of the art

Hi,

what is the current thinking on using 64 bit Ubuntu?

I have a new laptop with 4GB RAM to load Ubuntu on. I want to import
data from my previous 32 bit system. I don't use video applications
beyond viewing the occasional YouTube. I'm not what you'd call a power
user, more a dabbler. As far as I can make out from slightly dated
discussions, 32 bit these days can access almost all the 4GB RAM, and
has no significant speed hit, whereas 64 bit suffers from a smaller base
of usable applications. So I may as well use 32 bit. Is that an accurate
assessment?

TIA for your input