mate you're going to have to figure that out on your own. If you only have 600k Hilton or Marriott points, and this wipes you out, probably not? If you have 10mm, then yes? We don't know how you use those points, how many you have, how valuable they are to you, etc. and hence we can't really tell you what to do.

All we can tell you is that
1.) PEY is not "Economy Plus". I primarily flew UA before moving to CX in Hong Kong. Economy Plus, for lack of a better word, sucks compared to CX's PEY. The CX PEY seat is different - most importantly, bigger - than the standard Y seat. In the 747, PEY is 8 across while regular Y is 10 to give some perspective. I slept in the PEY seat once on a longhaul flight and frankly got a better sleep than I usually do in J or F. The food served are business class entrees. Many of us have commented on here how PEY is not too different from CX's "business class" of 20 years back. I never thought I'd agree with CX corporate, but....PEY definitely is a different "class" than regular economy. Everyone is now just so used to economy = seat and business = bed, but this is really a differentiated and significantly upgraded seat.

2.) Upgrade availability will be tough for you to score, as a non-elite CX member. I recommend doing more research on availability before you transfer your other program points to Asia Miles. I don't think you can hold an upgrade without having the Asia Miles ready, so you've got a slightly dicey situation if availability is limited because you're going to have to do the transfer first, and then secure the upgrades.

3.) Asia Miles are more "expensive" than other programs (in conjunction with above). There is an inherent cost incurred switching miles/points to Asia Miles, because Asia Miles get less bang for their buck. So the result of them being more "expensive" is really that you get less value. The point of this is you probably don't want to get stuck with Asia Miles if you can't score your upgrades, so be prudent and do your homework before you transfer. Most important factor is the probability if you actually scoring the upgrades based on CX availability.