A VQ35DE is a worthwhile swap. Yes the VQ35HR or VQ37HR have more +s, however they are way more expensive, harder to source than a VQ35DE, and there aren't as much aftermarket yet compared to the VQ35DE. Also, the VQ35HR, VQ37HR, and VQ40 all share the same block (VQ40 block) which is taller than the VQ35DE block so vertical clearance may be an issue (maybe the dual intake plenum helps this, not sure) and you need to source the correct tranny (07+ 350Z, 08+ G35, etc).