I bought this about a year ago as an upgrade to an ageing multi-effects unit I'd been using within my pedalboard (specifically a Vox Tonelab SE). The Plethora attracted me due to the simplicity of its design: various sets of pre-programmable boards consisting of up to 5 pedals, with the option to include external effects as inserts at any point in each board. The array of TC electronics stomps available was also a major attraction - I already had the Flashback II, so had some experience with their gear and working with toneprints. Having watched demos of the Hall of Fame II, I reckoned the pedal would justify its price based on those two alone.
A year later, and I can say that this is far and away the most versatile and useful pedal I own. It's brought a whole additional dimension to my playing: with so much scope for creating lush soundscapes, there are literally endless hours of fun on tap. The preset patches offer some really nice harmoniser and octaver effects boards, typically with useful delays and reverbs alongside. I've been pleasantly surprised by how good the pitch based effects are; the Brainwaves pitch shifter offers really tasteful harmonies, while the Sub'n'up Octaver has become a favourite, really excellent for adding weight to single note riffs, or even for overdubbing a bass line using a looper. I'm less of a fan of the chorus and flanger effects - there is by no means anything wrong with them, but they are just not effects that I tend to use in my playing.
I really like the ease-of-use of the pedal. Tweaking settings is really straightforward - just flick the switch from play to edit, adjust whatever param you need to, and then flick back to play mode. All the tweaks are instantly saved. Simple.
The included toneprint presets are also excellent, very usable and typically the kinds of tones we all search for but struggle to get right. My go-to delay is the Echoplex toneprint: try increasing the delay time and number of repeats, then strum an Em9 and pretend you're David Gilmour. Manna.
I've used the Plethora in band practices, and find the display is a huge help; it's clear and bright, and the white LEDs make it very easy to see which pedals are on at any given moment.
If I had one criticism, it would be that switching between boards on the fly isn't so easy; you can do this by stomping on switches one and two, although I often find I end up simply switching on or off whichever effect is in either of those slots, rather than changing boards as desired. It takes some practice to get this right, although you do get used to it.
Overall, I can't think of a better value pedal for the money. Considering the range of effects included, and the quality, the only competitor in my eyes in the Helix HT stomp. While also an excellent option, it's much less flexible and offers only three stomp switches. Highly recommend the Plethora!