I would go for RH450 if I were you. I didn´t ever had Little Rocker, but Little Mark II was my previous amp and now I have Staccato´51...both are great, but for me tc wins because of its features. It´s true that tubetone isn´t very good if you want to make some very overdriven sounds, but if you only want do make your sound dirtier, it works great in my opinion. To achieve overdriven sound I use my B3K and combine it with lightly overdriven setting on my head.
3 presets are great if you use more than one instrument. Those presets are saved and doesn´t matter what do you do with knobs on your amp while moving it. You set your amp, press buton and you have your sound everytime and everywhere...so no sound laborating before every gig. Built-in tuner is great feature in any case.
I have my tc head more than year and half and there was no problem with it.
I would recommend you to compare sound character and versatility and if you like both, go for tc because of additional features.