Both lounges are excellent. The JW is larger, and has an outside patio area. The REN has a better view. There are more food options at the JW, but both have made to order eggs for breakfast. I have found the staff/service in the REN lounge to be outstanding.

Since BKK is such a great food city, I prefer to eat out for lunch, then have snacks and drinks in the evening at the lounge. You can make a nice meal if you want - you will not go hungry or be disappointed with either choice.