I have one and used it for awhile with Elac DBR-62 speakers, now on the patio with Revel M80XC speakers. Works great for both and there's no issue with the low end - when the treble knob is all the way to the left it acts like a power amp with no EQ applied. What you are probably experiencing is comparing EQ vs no EQ and of course with EQ you get a boost in the bass which makes it seem that bass is weak without EQ.
I've also done a comparison of the frequency response on the Elac DBR-62 with Nobsound TPA3255 vs March Audio P452 (Purifi-based state of the art amp) and there was no measurable or audible difference.
The EQ knobs are very useful btw - my Revel M80XC do have a sharp drop off below 100Hz which matches
Amir's measurement of M55XC and the sound was very bright and lacking "body" - here's my full spectrum pink noise RTA measurement with REW and calibrated UMIK-1 compared against my preferred Harman-esque target:
With Treble at 3pm, Mids at max and Bass at slightly below max on the amp the sound became full and pleasing, here's the post EQ adjustment measurement:
Still not perfect, but very listenable and enjoyable. Tried a parametric EQ to perfectly match the target and got a slight improvement, so an order of Minidsp 2x4 HD is on the way.
My point is though that having EQ controls on the amp is a very good thing that can transform your sound for the better and makes this amp a great value for the price.