Quite a few people have stayed at the Park Lane and there is a master thread - generally it appears to be a better lounge experience that they enjoy. The W doesn't have a lounge, but with status you will get some welcome drinks vouchers: The Park Lane, Hong Kong, Autograph Collection [Master Thread]

The two hotels are quite different in terms of location - if your priority is easy disembarkation from the airport express then yes the W can be done entirely with walking, whereas the Park Lane (as with most Marriott hotels in HK) will require a short taxi ride, where the only inconvenience tends to be the need for physical HKD cash to pay.

Arguably with lots of luggage a cab may even be easier, by which I mean your choices when using the airport express are:
For the Park Lane (or most other hotels on HK island): Arrive into Hong Kong station, the taxi queue is about 10m from the train exit - though it can be a long queue. The taxi will take care of the luggage (HKD6 per bag into the trunk, probably HKD50 for most short rides)**
For the W (or Ritz Carlton): Arrive into Kowloon station, go up escalators, exit into a shopping mall, up another set of escalators and then follow the signs through the mall (all under cover and air-conditioned) for about 200m (W) or 300m (RC + a few more escalators)

**In the past there used to be associated hotel shuttles that would make the arrival super smooth, as you replaced the taxi with a point-to-point shuttle bus running very regularly, but very few of these now exist post COVID, and they don't look likely to be coming back as a result, sadly. See the live list here, that includes a few Marriott hotels like the Courtyard and Le Meridian: https://www.mtr.com.hk/en/customer/s...e-service.html