Not all ABS filament is created equal. Variations in composition affect the thermal properties of filament. In your case, for example, it would appear that XYZ filament dissipates heat more rapidly than your monoprice filaments, or perhaps, if carl_m's suggestion fixes your problem, it may be that XYZ has better bed adherence properties than your monoprice.
Tension on your extruder, within reason, should not have the consequences you describe.

This. I've had my Davinci Duo for about a month now. Put Repetier 0.92 on it about 2 weeks in, using Simplify3d fronted now which gives me a lot of control over extruder settings. Results with and without stock firmware are very different.

Stock Firmware:
-- XYZ Carts: work reasonably well, at least for small prints. Larger prints are a challenge, and detail is only so so.

Repetier Firmware:
-- XYZ Carts (Red, White, Orange): It's possible to dial these in and get decent results. However, I've not been able to replicate the quality from the stock firmware. These exhibit issues with adhesion and bulging. Keep in mind my lack of experience. My suspicion (based on experience with other filaments) is that this is cheap filament. Changes made in S3D extruder settings seem to have contradictory results.

-- ORD Solutions Glow In Dark ABS filament ($20 from Amazon): This filament was a great to work with. Small and large pieces exhibited no adhering or bulging issues. Changing settings in S3D had predictable results. Really forgiving to work with.

-- Hatchbox ABS Silver 1.75 filament ($20 from Amazon): Just started working with this, but effectively same results as from ORD Solutions. Very easy to work with this filament and changes I make have expected results. Again, really forgiving filament to work with.

-- Microcenter 1.75 ABS Red ($15 on sale): exhibits many of the same characteristics as XYZCart filament, if a bit more predictable. Small prints work well, larger prints are almost certainly destined to fail without a lot of prior testing and close watching.

My conclusion is that filament vendors do matter. I had initially thought that filament was basically a commodity and would buy whatever was cheapest. Instead I'm going to be careful who I buy from: ORD, Hatchbox, MakerGeeks and ZenToolworks are brands I know will work based on my or recommendations form folks with far more experience than me. In terms of wasted time and filament, I believe it's worth paying a small ($10) premium for filament that I trust.

I have found there are two approaches to the problem. 1) slow down the print rate (to give the last layer more time to cool) and/or 2) blow air over the print for the first 20 or so layers.

Placing more than one of your small cubes on the print bed (try 4 -- and spaced a good distance apart) is an indirect but often effective way of slowing your print speed.

The downside of slowing down your print speed is that you dramatically increase your print time, which is unfortunate because you only need it to be slower for the first few dozen layers. The use of a slicer (such as Simplify 3D) allows you to change the printing speed for different sections of the print, so you can have the extruder traveling dead slow for the first layer, slow for the next 20 or 30 and then up to regular speed for the balance of the print.