ijgordon, I also came from Grand Central. Its very easy to catch the "7" to Times Square, and then get in the "A" or "C", which lead quite close to the Acela area. However since you work near Grand Central, guess you know all that, and aren't in quite the most convenient area for these transfers, or else you avoid the subways at all cost.
Also, it is my understaning that Acela is the only Amtrak club that PC members have access to.