Is your dummy load a home made unit?
 
I also notice Rain's comments on the H&K amp when reading back through the thread last night.  The 5w head appears to come with a load switch and Redbox built into the head.  That is very interesting.  Looks like the Redbox may be limited to a 4 x12 cabinet sim.  I remember demo'ing that head last Summer and being pretty impressed with the tone out of that little 5 watt head.  One of my newer guitar hero's, Paul Rose, is now using that little head in the studio and the 36w unit live, I believe. 

Yes, my load is a big honkin' wirewound resister I put a 1/4" plug on years ago.  These things are kinda' spendy if you go out to buy one today.  Here's an old SOS article ... http://www.soundonsound.com/sos/1994_articles/apr94/dummyload.html
 
I looked at TM18 for a while, but for some reason reverb was left out of the head version of the amp.  I also considered considered the Carvin V3M, but couldn't stomach the idea of loosing a ton to shipping if I returned the unit - no place to try one out.  That's when I "discovered" the Laney IRT Studio.  It's a better fit all the way around and will end up costing me $13 if I return it.
 
There are options for tweaking the RB5 sim.  Vintage/Modern, Tight/Loose and Large/Small.
 
You have to look close at amps with built-in DI.  My HT5 has DI, but it is purely preamp.  The IRT has PA DI, but with nothing plugged into the speaker output, the amp operates 1W regardless of the input used.  To get it into 15W silently, I will still need the external load.  I'm not sure of the details on the Tubemeisters.  I read a lot of mixed reviews on the TMs that lessened my enthusiasm.  The main complaint was in trying to get crunch instead of full-on distortion.
 
I couldn't find a lot on the V3M.  A few users that liked them, but no REALLY big cybersmiles.  Then I noticed 3 or 4 of them on CL within a 2-state range ...
 
For now, I have a decent setup and high hopes for the Laney  :)