For me personally, if I am going to listen to a mix or see a DJ live I would far rather connect with them through the choice of tracks they play.
Some of my favourite mixes of all time are the classic Sasha/Digweed mixes, and the '99 Oakenfold world tour mixes for the essential selection.
A lot of DJs would probably consider these sets ‘boring’ by modern standards as they are little more than standard “A-B” mixing but yet they connect with me on a level that no amount of trick loop/sample/effect mashing ever does. John 00 Flemming is another example who still adheres to this philosophy, in fact I believe it was him who wrote an article on the reluctance of many modern clubs to book DJs to play 3 or 4 hour sets these days.
There is certainly a place for the exciting technical stuff, and indeed I enjoy watching videos of people really pushing the equipment to it’s limits, chopping stuff up, using acapellas etc (Dj Antonin being a particular favourite of mine in this regard), but where I draw the line is going to a local bar/club and having DJ Ego mashing up top-40 stuff to the point of playing a minute or so of each then slamming into the next one. You see groups of people (particularly women) who hear a song they love, make their way to the dancefloor and just as they get there DJ Ego has slammed into his next mashup so back they go to their seats/the bar.
As for playing, I generally prefer the first approach and this is what I will use in any mixes I put together, or when playing out, and it seems to get the most appreciation. I do however love messing around when I am playing for myself, trying out different techniques and playing just specific bits of tracks cut up with loops & backspins etc.
However I feel the only people who really appreciate this stuff is other DJs!
It’s also worth pointing out that different genres suit different mixing styles. If I am playing some funky house stuff I’ll often use shorter blends paying particular attention to not have keys/vocals clashing, if it’s happy hardcore it will be short-ish blends using the EQs as kill-switches (to swap bass over etc) or slamming the channel faders in & out, using quick filter sweeps on the buildups to transitions keeping the energy level as high as possible. Trance will be much more sutble, using tracks that really blend well together with much longer, subtle mixes, carefully working the EQs to transition as seemlessly as possible.
There is definately a place for all, but if I am listening to a mix/DJ its all about what tracks he/she plays that makes me have an awesome experience- too much chopping/mashing/EFX and not enough actual music spoil it for me 
there are lots of very very technical djs who make musically good mixes