Based on my experience with Both cars I would recommend the Xray over the TA04 TRF version.
Apart from being a little easier to adjust by the way of clip in spacers the Xrays Quality of materials leaves the Tamiya behind.
The Tamiya is a very well made car and I like it very much but the materials used in the Xray are second to none.
Just look at the things like the Hudy Spring Steel Swing arms and Turnbuckles as well as the Quality of the finish on the Ball diff outdrives, the finish and quality is impeccable. The Tamiya just don't use the same quality materials for their swing arms, turnbuckles, outdrives etc.
The Xray also allows Many more Battery positioning options for altering weight distribution.
You will find the cost of the basic parts for the Xray and Tamiya comparable when you look at things like the lower arms etc and other "Breakables". Some option parts for the Xray are very highly priced but they are usually Items you can easily live without any way.
If I was given the choice today of either a TA04 TRF or an Xray Evo 2 I would opt for the Xray without hesitation. The same verdict would apply if the TRF414MII was Included in the choice...