I didn't really like the plug in, but I don't like any plugins when it comes to distortion. A discussion for another thread.
I tried the Helix in a shop recently and was impressed by the Marshalls, which I thought really bad on the POD HD. The Plexi on the Helix and the JTM 45 are quite good. However, at that price range the AX8 is also a worthy contender.
The LT has all the features I need apart from SPDIF. One is for sale used for a good price, its a month old.
If someone who is more technically minded about SPDIF than I could chime in, am I going to get the same features as POD HD when recording SPDIF with the Helix LT? What is lost by the option of converting to SPDIF, as opposed to a dedicated SPDIF?