Upgrade advice: 105 or Ultegra for all-season bike?

Alternative to long reach brakes - long reach pad holders. 

http://www.ebay.co.uk/itm/AICAN-Aluminum-Bike-Bicycle-C-Brake-Shoes-for-Shimano-SRAM-Black-/201359303099?hash=item2ee1f321bb:g:sxQAAOSwl8NVZson

http://www.bdopcycling.com/BDop%20Offset%20Holders.asp

Neither are the cheapest of options, but they may open out alternatives for you.

Personally I'd be more inclined to go the 105 route. Not helping things are reports that Ultegra 6800 cranks coming apart where the two halves of the drive-side crank arm are bonded together. 105 cranks don't use this two-piece bonded construction; they're solid-forged items that are simply hollowed out.

I'd upgrade to the Ultegra brake calipers if you're still on rim brakes, but other than that, 105 all the way.

For an all year all weather bike I'd stick with 105. I have bikes with Ultegra, 105 and Sram Force. The 105 is on my commuting bike and I treat it terribly but it just keeps working. I'd feel bad treating Ultegra like that. As for shifting I prefer the 105 as it has the long derailleur cage for a 32T cassette as opposed to my shorter 28T Ultegra cage.

Hmm... they look a bit rubbish...

If you get Ultegra you can always replace the 'consumables' with 105 when they wear out, if you want. It's all compatible. I am still using Ultegra 6600 on my winter bike.

I have 5 year old 5700 (105 10 speed) on my winter bike with shimano br r451 long drop brakes.  the groupset has probably done 20k miles, most of it in horrible weather on the back roads. I give it a wash when i cant tell what colour the bike is and oil and wipe the chain every few rides.

Its very reliable as far as im concerned and the shifting/braking performance is great when its set up right. When it comes to replacing parts like chain, cassette etc, there is always something on special offer somewhere online, i usually get a chain and cassette for £40.

The core bits of the groupset just keep on going. I strip it down once a year and clean and re lubricate all of it.

If you want things working reliably through the winter then get a decent set of fitted full mudguards. They help keep a lot of the gritty muck off the drivetrain, and that makes a huge difference in my experience, otherwise you'll need to be much more on top of maintenance, cleaning etc. Hope this helps

My winter bike came with Tektro long-drop brakes and they were awful, flexy and under-powered. I replaced them with Shimano R650 brakes (which I believe are Ultegra level?)  and they are like night and day, MUCH better braking.

Nah, for an all year workhorse I would be looking at 4700.  It offers great VFM (whole groupsets for as little as £250) and replacement of parts is dead cheap too.  As a Brucie bonus, 10 speed chains are less prone to those minor faffing issues of their 11 speed counterparts (as in no specific chain tools, lots of reusable chain links available, etc.) and there are no side plates that are finer than a gnat's chaff.  Thing is, well set-up and maintained 4700 is pretty blinking good in terms of performance, looks, durability and cost.  Yes, Ultegra is nice but who cares about the finer points of shifting quality when it is lashing down with rain and one is riding into a block headwind.  

Ultegra all the way -  as an awful maintainer of bikes I have consistently found it far more reliable when ridden and uncared for. In paricular 105 brakes - can't live with hard use and poor maintenance - I'm running some lovely 6600s still having on other bikes destroyed 105s so they are proper OLD!

Fact is the materials used and the engineering seem superior in ultegra. I know loads of people who use ultegra cassettes in an otherwise full DA setup - never a 105 - does that indicate anything?

Plus everything  is compatible so you can swap bits when unhappy-worn out...

 to DA of course - well 'your worth it' as the advert says!! 

Consumables are the same  -I'd upgrade the brake blocks once worn to swisstops flash pro - but that's me.

Difference is a small price to pay IMHO

I'd argue the other way and say go fo Ultegra if you can afford it.

In my experience, there are some subtle performance gains to be had from Ultegra over 105, the most notable of which is brake performance.

However the real difference I believe will be longevity, I would say Ultegra has more stamina than 105 if you start putting serious mileage on it. 

This is not just related to parts wearing out, but parts not quite working to 100%... my 105 5800 groupset has been pushed hard with lots of winter miles, and boy have I replaced a fair chunk of it over the past 2.5 years.

However, its the bits I've not replaced that are the problem... the brakes with the rough bearing surface that you can never get buttery smooth, the left shifter that occasionally sticks, the level blades that have worn through the paint... those little things are not big enough to be worth replacing, but do compromise your enjoyment just a bit. 

So I'd say, spend the money if you can, in 2 years you'll be pleased with your decision. 

From someone that have used tiagra,105 and ultegra I'd say go with 105 for the price savings.

I downgraded from ultegra cassette to tiagra and 105 shifters to tiagra, didn't notice any difference as far as ride quality goes. Ultegra would be your choice for weight savings mostly.