Motorola Droid : Performance Effect Phones Longevity Compared To Eris For Future?

looking for some educated feedback on this, is the droid really better in terms of power than the eris? i returned the eris because i thought it was too slow and didn't stack up to what the droid is, but was i wrong?

i look at the verizonwireless website and they have the same stats, except for the keyboard of course. but then i hear some htc users say that the eris is just as powerful as the droid and can do everything that the droid can in terms of performance. on the other hand i get people telling me that the droid is the 'powerhouse' and ive read that the droid is the 'high-end' phone. people have told me about better cpu/processor/memory - is this true and is it noticeable? and will it effect the phones longevity compared to the eris for the future? i heard that it will as more updates comes out... someone told me that the eris will never be up to par with the droid hardware wise and that the droid is the safe bet if you want the most from future updates ... also read that the eris will be 'long in the tooth' (old) faster.