Is 64 Bit Win 7 a problem?

I have a Dell Inspiron 15R i7-2670QM, with 6GB 1333DDR3 SDRAM with 64 bit Win 7 professional, and an old Vostro 1510 Core 2 T8300 with 4GB of 667DDR2 SDRAM with 32 bit Win professional. As I am 'upgrading' to the Inspiron, both computers have virtually the same software installed, although the Inspiron has some additional Dell installed software (but both have only Zone Alarm Extreme security AV). The Inspiron takes about 4.10 minutes from start to usable to boot up while the Vostro takes about 2.53 minutes. In general the Vostro is a much nimbler machine when running and closing down than the much more powerful Insprion which should be running rings around the former. In addition, Quicken 2012 has a refresh problem on the Inspiron that effects the cursor movement and makes it almost unusable, and I have had a few recent blue screen of death moments.I've run MS Fix It and checked with the Dell Tools and all the hardware and software check out. I run generally low demand software - word processing, financial, document processing, bibliography software, utilities, so nothing high demand.

The major difference between the two - in terms of software - seems to be 32 vs 64 bit Win Professional. I thought 64 bit Win would be better and so ordered it, but should I down grade back to 32 bit? As it is the Insprion is a significant downgrade from the Vostro in terms of usability.