Yes, adjusting status in your case is legal. Once a proper I-485 is filed, you would be authorized to stay in the US until the I-485 package is either approved or denied. However, there are several differences. Good luck on your journey.
Adjustment of Status
Expensive
Requires I-485, I-765, I-131 packages to be filed.
Spouse can not leave the US until she/he receives approved Advance Parole (approx 3-8 months)
Spouse can not work until she/he receives EAD (approx 3-8 months)
Some people have had problems with driver licenses, Social Security cards, leases, bank account during this period
Spouse will not receive Green Card for many months after Adjustment of Status is filed.
Legal residency does not begin until the Adjustment of Status has been approved.
Applicant cannot file for citizenship until after having Green Card for 3 years (which is normally months or more after filing the I-485).
CR-1
No Adjustment of Status(I-485, I-131, I-765) required.
Spouse can immediately travel outside the US
Spouse is authorized to work immediately upon arrival.
Spouse receives Social Security Card and Green Card within 2 or 3 weeks after entering the US
Opening a bank account, getting a driver's license, etc. are very easily accomplished with GC, SS card, and passport.
Spouse has legal permanent Resident status IMMEDIATELY upon entry to US.
The clock for citizenship filing starts immediately upon entry to the US.
Visiting is allowed during the process (at the discretion of CBP).