...past is my biggest obstacle.?
but could the enclave turn things around for their reliability scores?

They are both great cars if your leaning toward the Buick but worried about reliability thren wait untill the next years models after they fixed the problems with the Buick. The only thing i liked more about the Highlander was the backup camera which was pretty cool. Do yourself a favor and go with Buick.

then go with the toyota.

What do you mean the Enclave turn around with reliability scores? It is a brand new model for 2008, so there is no or hardly at all any recalls. It is supposed to have very good reliability. It has a very nice interior and modern/sleek exterior. I would totally get it over the Highlander. Although, I would rather get one for next year's model just in case. Usually, once a brand new car comes out, it will have kinks its first year. As the second year, third, fourth, and so on, the manufacturer will work out the kinks as each year goes by. There may also be some improvements done to the car too. The 2008 Highlander is brand new too, so there may also be a few kinks in it. I would still pick the Enclave because of its comparable reliability and cooler styling. It is classier and rides nicer too.