Was just about to round up when I spotted your post.
Now have a 1000 miles on them and very pleased with the result.
One thing I have done since my last post is to replace the standard exhaust system. Think I must be getting too old for these things, noise was driving me mad!
I found that it increased the vibration slightly and made me do silly things occasionally. Guess it's not 1973 with a Yoshimura pipe on my Honda 500 four.
So, what improvements have I found with the AF-XiED units?
The engine is now sooo flexible. Tickover has dropped to around 1200rpm so have had to re learn moving off a bit so that I don't stall.
In around towns I'm short shifting up at only 3000rpm, the engine just pulls relatively smoothly from very low revs. Gear changes are much smoother, too, particularly in the higher gears where I rarely have to use the clutch.
It's the throttle roll ons that I really like. Sitting at around 60 mph in top and ready to overtake, opening the throttle and the bike just surges forward without having to drop a gear.
The mid range is really strong now.
Not sure if that was one of the things that I didn't like about the sports exhaust system. While it did seem to let the engine 'breathe' better at the upper end of the rev range, I felt that there was reduced back pressure which meant a loss in the mid range. To me, that's what the GS engine is all about. BTW silencer currently on eBay starting at 99p if you don't value your hearing.
Was out on it this fine afternoon and love the smooth, flexible pull of this engine. If only BMW had been allowed to put this engine out without the restrictions it would have been a peach!
Downsides?
Fuel consumption increase by maybe 2mpg but may be down to a more, um, enthusiastic throttle hand.
For the R1200 engine two units are required which works out a bit pricey, but comparable the the cost of a new PCV or a Hilltop remap.
Unfortunately, they are unlikely to appear on eBay or the 'Items for sale' on the forum for a while as they are still rare here.
So which one?
Of course, the Hilltop mafia are going to say their choice is the best and while I'm sure that it is a positive improvement over stock, I genuinely would doubt that it is any better than the gains made by using AF-XiED units. Until we have someone who has sampled both, that will have to remain a matter of personal opinion.
In terms of cost, it's around the same. Although, speaking as someone who has had their own business, you must factor in the cost of getting there as well as travel and tuning time on the dyno.
That's a big variable, I know. For me, living in N Ireland, too big.
You need to be sure that this bike is really, really, really, really a 'keeper'. An expression I've noticed used a lot on the forum. Because when the bike goes, so does your re-mapping. Wouldn't mention it to the prospective buyer as a selling plus either. Because unless he's an aficionado of the forum and knows what you're talking about, he'll run a mile! I would.
One forum member has spent a grand on remaps so far.
The PCV is a good job. Had one and was very impressed with it. Positives are it was cheap to buy second hand, relatively easy to install and made the bike run noticeably better.
Downsides are dubious waterproofing on some of the connectors. Far too many connectors needed anyway. Bit obvious that you have one if you 'forget' to tell your insurance company, too.
The mapping is 'fixed'. That is, the fuelling did not adapt to changes in temperature, exhaust/filter changes, engine wear, etc. unlike the benefits from the standard ECU.
You were either relying on getting it dyno'd or depending on the fuel map of a GS that was 'similar' to yours but currently riding around California.
So spend the money on a dyno run! Great! Except that there's still no adaptability and the new map is only valid for the conditions on the day that it's dyno'd.
Fit Autotune units! Add another couple of hundred quid and even more cables and connectors. Been there, done that. That's the point I began to look for an alternative.
So back to the AF-XiED units. Discrete, if you like them to be. No dyno required. The ECU 'learns' the new AFR setting and applies it as you ride. It adapts the AFR to your personal riding habits. I think one of the reasons that people are suspicious of these units is that no dyno time is required. Doesn't need dyno time so must be crap, right? Booster Plug mentality, I think.
If you want to know how they work, see Roger's thread if you have a spare week. It's all there.
Easily fitted in half an hour if you are taking your time to make a neat installation. You have a certain amount of adjustability with the AFR if don't want to use the recommended settings.
Selling that 'keeper' for a new LC?
Removed even more easily and has a resale value. Or else you can fit them to your next bike if you want to.
I would recommend any one of these options, having sampled two of them myself. As I say, I've no reason to doubt that a Hilltop is a valid choice.
You will have a bike that is much nicer to ride, keeper or not.