Welcome regular new visitors (this post gets a lot of traffic!) - my opinion after a few years hasn't changed on this fingerboard.....
An excellent training tool for anyone looking to develop strong fingers. A great supplied program included also.
Note: like all supplementary training, a fingerboard is only a supplement to actual climbing. Additionally, It'll only give you the gains if you're consistent with it (like any proper training).
[Fingerboards are like tuning an engine while it sits outside a car to have more power. Put it back into the car and the car can't use the power properly as the suspension/tyres aren't set up to utilize it properly yet, but with some tuning over a short period you get access to all of the gains]. My attempt at translating training :)
If you have access to one, I highly recommend using it.
A couple of years ago a new board appeared from Eva Lopez, most recently in the headlines for climbing 8c+. But the board really intrigued me as it came based off some proper research and the concept seemed sound. We were lucky enough to end up with two of them at Awesome Walls and starting in around October 2012, I committed to putting in several months on the board as a grand experiment on myself (the obvious benefit being that if it worked......).
My own outcome from usage
Overall the board was great - I saw progressive, continuous gains over the several months (there was dips in performance throughout those months but that is normal as part of any training program) I used it initially. Yes, my fingers got stronger. Like always, after using a fingerboard for gains, there was some 'bedding in' of the strength so that I could use it while climbing both indoors and outdoors, but it absolutely transfers to climbing.
Of course, it's no different to many of programs in that if you follow something consistently, you will see outcomes. But the level of effort required which fits comfortably in around other climbing (the hangs took a grand total of about 45 minutes per week), the detailed information on what to watch out for (in relation to reductions in your previous levels from tiredness, stress, etc) provided by the information sheet, and the variation of the weighted and small-edge hangs ensured I saw very significant gains since starting using it. If you can get one, it's an excellent fingerboard.
But again, it'll only give you the gains if you're consistent with it.
*Note: I'm not giving my own levels (rung size or weight added) on it as they will be different to your own. So long as you're hitting the targets as specified by the program and sticking to the relevant difficulty level for you, you'll see the results in time.
The board is essentially a row of incut edges starting from as large as 24mm (on the Progression board, the 'easier' version) and all the way down to 6mm on the Transgression (harder). The bottom three rungs of the Transgression can be seen above in the photo; 8mm, 7mm and 6mm. Most importantly, the board also comes with a poster with detailed instructions on how to follow a program of weighted hangs and small edges. The poster makes the board, giving useful informative guidance in a very simple program (although it does take about 10 minutes to read and work out - and in this day and age, where most people won't have even read as far as this line, that might be too long for most!. I'm not going to give too much details away of how the program works but it follows a format akin to high/low training (some info in a climbing-related context at that link).
The other part that is worth its weight in gold is the level of interaction by Eva through Facebook and Twitter and her blog. I had a couple of queries and there were some very helpful responses directly from Eva personally. There's also a great set of videos demonstrating how to use the board correctly on her site now also.
p.s. the rumours of it wrecking skin
I also heard stories that the board was a skin shredder, my skin would fall off and all I would be left with was bare bone (o.k. maybe not that dramatic but did you not know what you read on the Internet is true!). My own experience, following the supplied plan exactly which involves training on it twice per week, was nothing like this. Yes, the edges are sharp and it did cut skin but it only ever caused this problem if I wasn't strong and was largely just biting my skin into the edges to hang on, and over-using the board or trying it when too tired. So I found that the board was working to my benefit, ensuring I only used it when fresh and ready for a proper training session. Try and use it multiple times per week (like many people attempt with other fingerboards), and yes, I suspect you'll ruin whatever skin you have left (considering you're climbing so many days anyway).
Update 10th April 2014:
Eva posted this review on her own blog - and added the comment:
"There is now a NEW VERSION of Transgression, which is made with polyurethane (lighter) and I think that it has less sharp edges than the previous version (Neal's, which was made with Polyester resin)."
The Negative (if you can call it that)
Possibly the only negative of the board? It's price. If you can afford the price, it's seriously worth considering (and at the very least, making sure your local climbing gym gets one in :).
If you have access to one, I highly recommend using it as part of planned training programme over a consistent period of time.