Depends really.
It depends on the model of Elise or VX220 variant.
I've moved up to a 111R as for power delivery its probably the most similar.
I wont talk about the benefits as it is obviously a better drivers car and a better experience. But it isn't markably better all round and for pace its on par with the elise down a normal road.
As for cost,
Add 250 quid to the tyre budget (the rears die within 9k and cost about 300 but between them fronts are cheaper)
Servicing is a bit more expensive
However the parts..... i've been fairly unlucky (although all has been covered by good will or warranty) and Murray lotus have probably spent 2.5k in doing bits and pieces since i picked her up 7 months ago.... one item the throttle body went which was a £987 part then you've got labour!!
The big thing though and something you wont get in a V6 is the MPG it is as good or better than the 182. This means that i wont have to worry about the cost of petrol or think wow i cant afford to go out for a random run.
If you go for it get a lotus stage 2 exhaust and then drive everywhere in 2nd gear for the pops and bangs