We say it's the same here, too. But there's a little controversy...check out this letter to the CPSPList a few years ago from a Ford engineer (now retired). The gist though is that the single LATCH belt like we have in the US on most seats is the same as a seatbelt, so in our case there may not be much difference. But for seats with rigid LATCH or probably the two strap design, it is possibly better, especially for the average parent who's not tightening belts enough.
CRS installation - LATCH vs. belts
"I feel that I have to chime in on this subject because I disagree with the party line that LATCH is just intended to improve convenience and reduce misuse, and its OK to just use the belts if using LATCH isn't convenient. It would be nice to be able to tell customers that their children can get the same protection using either attachment system, and that there is no need to install the CRS in a seat equipped with LATCH anchors. But I can't support that position because of test results that I've seen. Ford has run a lot of tests of child seats installed with LATCH anchors and installed with seat belts, and I see a consistent and substantial improvement in performance using LATCH anchors and attachments compared with belt installation, even when both tests used snug tether straps.
I have also examined NHTSA's NCAP CRS tests. Those tests did not show a consistent or substantial difference between belts and LATCH
installations. But the child seats in those tests were installed very tightly, with less than 1/8 inch of lateral movement at the belt path under a 50 pound lateral pull. We can install child seats that tightly, but very few parents consistently install child seats that tightly. Ford tests child seats using more typical belt tightness.
The difference between LATCH and belt installation may be even more important in side impacts, especially with some child seats. Child seats with rigid attachments (like the Britax Expressway ISOFIX) or with two separate straps and adjusters (like the Fisher-Price Safe Embrace II)[Britax Marathon] are more stable in side crashes than child seats installed with lap belts or with a single LATCH belt and single adjuster (like the Cosco TRIAD or the retrofit LATCH kits)[Sunshine Kids Radian].
GM market studies several years ago showed a strong customer preference for dual straps and adjusters because it is much easier to get a tight fit with dual straps and adjusters, but many child seats use the single strap and adjuster LATCH attachment system.
I think the decision about what to recommend if the LATCH system doesn't provide a tight installation is a difficult one. If the belt and tether
installation is very tight, as in the NCAP tests, it is probably just fine.
Personally, if I couldn't get a tight fit with LATCH, I would get a child seat that did provide a tight fit using LATCH anchors.
Regards,
Paul W. Butler - Ford Advanced Safety & Regulations"