Whats cool about the Rumble is you can use it to monitor as you play at any level. that doesn't effect the DI output. You set the record level with the "Gain" and you can set the Master at any level.
I have it under my desk and so it's like 5" from my leg! Nothing like "feeling" what your putting down without latency. 

Cactus Music
OK here's the deal- The P bass Lite only goes to E -  the paid full version goes to low B just like a 5 string. So if you like the VST you need to anti up and buy the full version. 
I have a lot of songs that use low D so I'll have to think about this. I think I'll just watch for a deal. 

I was wondering about that...  I like the VST, so I'll also watch for the deals, but will likely forget to...  
 
Thanks all for the contributions...much appreciated.  I play tuned down to Eb and record that way as well, I know there are work-arounds but I try to keep it simple, as I'm not a techno geek, just do and learn enough to get by on...  will get more into it as time allows. 

I'm playing with the Lite version and do like what it sounds like for certain songs. It's more Piano Bass than SI. Like you have new strings. 
What I've done is I highlight all the notes below E and drag them up an octave.  I then Have to fix a few runs that become illogical but that doesn't take long. Will see how it sounds through the PA. That's the Acid test. 
I too will keep an eye out for a sale of the full version. 

OK, got the Ample Bass P Lite II working for me in Eb...
It finally dawned on me that rcklln said to just grab a tuning key and turn it...  d'oh!
So here is what I did in case someone else plays in Eb..... I think it will also go down to D, but haven't tried it. 
 
Insert Ample Bass P Lite synth into Sonar project;  Melodyne the section of bass guitar track you want to play in ABP Lite; drag and drop Melodyned audio into ABP Lite synth track; click on the now midi'd clip to highlight, right click and select "transpose";  transpose it up 12; go to ABP Lite VST window and click and turn on tuning pegs to lower to -1 (Eb).
 
Not sure why the last step works, but it does, and extends the mapping on the VST displayed keyboard down to the Eb black key. I assume it will do the same if you tuned the bass guitar down -2 to D, and allow you to play the D note. 
 

Cactus Music
I'm playing with the Lite version and do like what it sounds like for certain songs. It's more Piano Bass than SI. Like you have new strings. 
What I've done is I highlight all the notes below E and drag them up an octave.  I then Have to fix a few runs that become illogical but that doesn't take long. Will see how it sounds through the PA. That's the Acid test. 
I too will keep an eye out for a sale of the full version. 

I found the free Ample Bass P lite II last year and was impressed.  It sure sounded like my old P-bass, without needing to put on new strings, get in tune, etc.
 
Then I found the Ample Metal Ray 5 on sale.  It is a sampled Music Man Stingray5.  It is done with picked articulations, so it has more punch and attitude than the fingered P-bass samples.  Can tune down to A0.