I wouldn't rush into it with all the brass bling just yet. With a lightweight body, you may not need any of it. Low weight can be very advantageous in regards to crawling. My TRX4 platform is carrying a large and tall Defender body with plenty of scale bling, so it's rather top heavy and needs...
Having all 3, I highly recommend the TRX4 platform. It's just a level above the other 2 brands in regards to trail/crawl performances.
The SCX10iii 2 speed is absolutely weak. It's an increase in maybe an extra 2mph. Axial obviously put no thought into that design. I went through 3 of those...